Believers and emigrants. 620-680, generations 432-434

This period was world-changing. It saw the appearance of a new idea, a new frequency in human affairs. The effects can be traced through to the leap in learning that happened in Baghdad a century later, to the Medieval enlightenment in Europe a couple of centuries after that, to the Renaissance in Italy, to the Enlightenment, to the industrial revolution and so to today.

And it started with one man – Muhammad.

However, in order to get a sense of what was going on at the time, we need to remove several layers of padding and interpretation. Most of what was written about Muhammad was put to pen over a century later. My experience tells me that old people’s memories are sometimes unreliable, and even more so when we are dealing with memories of memories from a century or more before.

There are two documents from the arabic-speaking world that can be dated to the period in question: the charter of Medina and the Qur’an. They seem a sensible place to start.

The Qur’an is not a historical document. It is a series of revelations, of perceptions, insights about the human situation and its relationship with God. It has very little reference to external events.


Pages from the Qur’an, written during or shortly after Muhammad’s lifetime, recently discovered in Birmingham University. Image taken at Birmingham Museum, UK

The charter of Medina is the treaty document between the the emigrants (referred to as the Quraysh) and the inhabitants of the oasis of Yathrib, henceforth known as Medina. The original has been lost but there are several copies, all similar enough to suggest that they come from one source document.

The first paragraph reads:

“This is a document from Muhammad, the Prophet, governing the relation between the Believers from among the Qurayshites and Yathribites  and those who followed them and joined them and struggled with them. They form one and the same community as against the rest of men.”

Taking these two documents as our main reference brings up some difficult issues. I’ll start with what is for me the most difficult.

There is no mention of Mecca in the charter of Medina. In fact, there is no mention of where the Quraysh emigrated from. In the Qur’an there is one mention of the ‘hollow’ or valley of Mecca, as follows:

“It is He who restrained their hands from you, and your hands from them, in the hollow of Mecca, after that He made you victors over them. God sees the things you do.” (sura 48)

This would suggest that there was a valley of Mecca in which a conflict took place which was won by Muhammad, and whose aftermath was not as violent as it could have been.

Further, there is no mention of Mecca in any other contemporary, non-arabic document. In fact, there is as much evidence that Muhammad lived in Mecca as there is that St Peter lived in Rome six centuries previously. This does not invalidate or diminish the immensity of Muhammad’s achievement. It suggests to me that maybe some later commentators had an interest in locating Muhammad’s origins in the heartlands of the arabian desert, far away from the contaminating influences of Constantinople and Ctesiphon to the north. Almost as if they wanted to emphasise how what Muhammad brought was entirely new.

Which raises a question: where did the Quraysh emigrate from? The Qur’an mentions olives (which only grew in the Mediterranean). It mentions herding of animals and growing of crops, activities more associated with the fertile regions to the north or south of the arabian desert.

Maybe in the end it doesn’t matter where they emigrated from.

A second difficulty is about the term ‘believers’. The word ‘believer’ occurs more than ‘muslim’ in both the charter of Medina and the Qur’an. ‘Believers’ is a much broader term than muslims, encompassing those who believe in God (Allah in arabic) and who adhere to the earlier revelations from God – the old and new Testaments – or the latest one, the Qur’an. The charter of Medina makes it clear that the jews and muslims are distinct, with different religious practices. But they are all part of the community of Believers, the ummah.

This perception is confirmed by archaeological evidence. Several christian churches built in the period in question have been excavated. One in Jerusalem had an altar facing east and a prayer niche, a mihrab, facing south. So the different varieties of believers clearly saw no problem in performing their separate religious practices in the same space. When Damascus was taken over by the arab army, the church of St John was divided into two, so that the muslims could pray in one section and the christians in the other.

Nowadays, we are trained to think in categories: muslim, jew, hindu, buddhist, humanist, and so on. But the seventh century was a time when every valley, each village, each tribe had its own practices. Zorastrianism blended into hinduism and buddhism in the east, towards India. There were jewish christians and christian jews. Diversity was the norm. What Muhammad did with the charter of Medina was reach for an overarching criterion, the ummah that was higher than tribal obligation or religious practice and included all believers under its cover. The Qur’an also contains this view. Diversity of expression is not a problem so long as the core principles are agreed to.

This may help to explain another archaeological mystery. The arab conquests are almost invisible in the archaeological record. Usually when there is an invasion there is a layer of burning. Caesarea was burnt and the library at Alexandria was destroyed, but otherwise there is almost nothing. And that would make sense if the inhabitants of the conquered territories were believers, whose belief systems were regarded as legitimate by the invaders. It would have been in their interest to welcome the invaders. The non-orthodox varieties of christianity, such as the Copts in Egypt, were oppressed by Constantinople. The arrival of the arabs, fellow believers, may have been a welcome relief. It also explains why there was no particular push for conversion by the invaders. Why should they? All were believers.

So when did it change? When did islam separate out? When did the community of believers split into distinct religions? The evidence says this was the achievement of the ummayad caliph abd-al Malik.  Abd-al Malik preferred the word ‘muslim’ to ‘believer’. Muhammad’s name was not written down (in anything that has been recovered from the time) from when he died in 632 or thereabouts until abd-al Malik had it put on the coinage fifty years later. When the Dome of the Rock was built in Jerusalem in 691, phrases from the Qur’an were selected to emphasise the distinctness of islam from christianity – that muslims do not accept the idea of the trinity, for example.

And so humanity had another established religion.

An accidental empire. 680-740, generations 435-437.

During Mohammed’s lifetime the Arabian peninsula was united into a single polity. After he died in 632 the expansion of arab-controlled land accelerated. The rate of expansion was astounding and unprecedented. The latest dynasty of the Persian empire, the Sasanian dynasty, had the misfortune that its capital, Ctesiphon, was not easily defensible against the arab armies. After losing a battle against the invaders in 636, the Sasanian royal family abandoned Ctesiphon. Once the capital was gone, the rest of the empire could be picked off bit by bit. The arabs repeatedly attempted to take Constantinople too, but failed. Emperor Constantine had chosen a defensible location three centuries previously, on a promontory encircled by the Bosphorus. So the Roman empire, although dramatically reduced in size, was not wiped from the map in the way that the Sasanian one was, and its rump continued to be administered from Constantinople.

Within fifty years of Mohammed’s death the Umayyad dynasty was established in Damascus. From this base it controlled the whole of the ex-Persian empire as far as China, a large part of the Roman empire (Anatolia, the eastern Mediterranean, north Africa) and, by the year 720, most of the Iberian peninsula. The map of the world had changed, irrevocably.

The Umayyads appointed arab governors to each region, who collected taxes and sent them back to Damascus. There was a vigorous slave trade. It was said that after the defeat of the Visigoths in southern Spain, 30,000 blond Visigothic slaves were on sale in the slave markets of Damascus. This was beginning to look more like an empire than a religious arising. The arab elite grew rich.

Tensions began to show. The arab rulers came from the desert of Arabia. Hitherto, their main contact with the empires administered from Constantinople and Ctesiphon had been as traders and raiders: people on the move, not city-dwellers. There were not many of them: they were a tiny minority in their vast unexpected empire. They did not have the infrastructure or the traditions to manage it. How to administer these lands and retain their distinctive identity?

One way was not to move into the pre-existing cities. In Mesopotamia the arabs set up encampments, which became garrison towns in Kufa and Basra. In Egypt they set up a semi-permanent camp on the banks of the Nile at Fustat, which is now a suburb of Cairo. They left the Roman and Sasanian administrative structures in place and almost untouched. For those living in the villages of the new empire, the regime change must have been hardly noticeable. The fact that the annually-collected taxes now went to Damascus instead of Constantinople or Ctesiphon probably didn’t impinge. Otherwise, life continued unchanged.

However, there was unrest. There were repeated uprisings all over the new empire. The arabs came with a powerful new religion and a book which proclaimed a bright future for the Believers. The book seemed to say that bloodlines and tribal loyalties were secondary to what a person chose to believe. For an open-minded, thinking person this appeared to offer a way out of their current situation . It was possible to be a part of this powerful wave that had swept over the world, simply by declaring one’s adherence to the new religion. But it didn’t work out like that in practice. When several hundred escaped slaves moved to Basra and Kufa and declared themselves to be muslims, the governor had them arrested, branded and sent back to their masters. Evidently, in this new world some were more equal than others.

The pervasiveness of slavery may have been an escape-valve. The slave trade was a fact of life, seen as a necessary evil. Attempts had been made since ancient times to regulate it, but never to outlaw it. This posed new dilemmas for the arab rulers. What was the legal status of the offspring of an arab father and his non-arab slave? Could they become a muslim? Over the years a complicated hierarchy emerged. A person with two arab parents was at the top of the tree, followed by one with one arab parent, and so on. There was movement between the categories. For example, the general who led the conquest of Spain in 711, Tariq ibn Ziyad, was probably an ex-slave. Gibraltar (Jebel Tariq) is named after him.

Another area addressed by the Umayyads was the coinage. In the early years of Umayyad rule the empire continued using the Sasanian and Roman currencies. This meant that, long after the arabs had taken control, images of the Roman Emperor were still on each coin in the purses of the traders of Alexandria and Damascus. In the 680’s the Umayyad emperor had his own coins made, with his image, modelled on the Roman solidus minted in Constantinople.


Here is a coin from 693, showing an image of the caliph Abd-al Malik. Courtesy Muslim Heritage

Whereas Emperor Justinian’s solidus had his image on one side and the christian cross on the obverse, Abd-al Malik’s dinar had an image of himself holding a sword on one side and the symbol shown here on the back of the coin. Evidently the muslim prohibition of depicting the human form had not yet kicked in. His image was encircled by the testimony of Islam written in Arabic: “In the name of God, there is no deity but God; He is One; Muhammad is the messenger of God.” Interestingly, Abd-al Malik had grown up in Medina, the final home of the Prophet and base for an uprising against Umayyad rule on the grounds that it was not following the way of the Believers. By placing the Testimony of Islam on his coins, maybe Abd-al Malik was nailing his colours to the mast.

In Abd-al Malik’s next minting, in 697, there were no images.


These coins were made compulsory throughout the empire. Persian and Roman coins were melted down and restamped, on pain of death. The language of the administration was declared to be arabic rather than greek or persian as it had been. The conquered territories began the process of cohering into a single entity, the dar al-islam, the abode of islam.

The people of the Book

Mesopotamia, known since ancient times as the Fertile Crescent, is rich in more ways than food production. For centuries it has been a place where learned people inquired into the nature of reality. It was a place of rich and fertile exchange of ideas.

But first, some background. To the west of this region was a great empire, referred to in our history books as the Byzantine Empire. But the word ‘Byzantine’ fell out of use in 330 C.E. When the Roman Empire was divided into a western and eastern half, the emperor Constantine established the capital of the empire of the east in the city of Byzantium in 324 and changed its name to Constantinople in the year 330.

Over the following centuries the western half of the Roman Empire disintegrated under repeated invasions from the north. The eastern half continued for another thousand years. The inhabitants of the empire ruled from Constantinople, which included the Balkans, modern-day Turkey, the eastern Mediterranean and parts of north Africa, referred to themselves as Romans.

Constantine also adopted Christianity as the official religion of the empire. Over the following generations scholars argued and agonised over the nature of Jesus. Was he human or divine, or both at once? Could a person so influential, so world-changing, have been a mere mortal like the rest of us? And if he was divine, what was the nature of Mary, his mother? They held councils to debate the question and came up with an official doctrine. Those who did not subscribe to the official view were declared heretics.

Many of those so-called heretics moved to Mesopotamia and joined the church of the East. The orthodox christians back in Constantinople disparagingly referred to them as Nestorians. The name stuck. That is the name used for the church of the East in my history books 1500 years later. (Nestorius was a bishop in Constantinople who had disagreed with the establishment over the term ‘Mother of God’ for Mary. His ideas were more welcome in the church of the East, but it was already in existence when he arrived.)

Byzantine, Nestorian … the third misrepresentation is ‘Zoroastrian’. This word was first used in the nineteenth century, to describe a set of beliefs prevalent in Persia since ancient times. This religion was traditionally founded by a man called Zoroaster, or Zarathustra who lived around 1000 BCE. Its heartlands were the mountains of Persia through to Khorasan in the north and east as far as India. Each region, each mountain valley had its own version of it. Further east, it contained elements of the Vedas. Shiva was incorporated into the belief systems, for example. Some adherents were vegetarians and pacifists who abhorred the unnecessary taking of life. In some regions polyandry was practised. This last appalled the incoming arabs, who described it as ‘wife-sharing’. To the west, it rubbed up against the values of the christians and jews (who themselves could not be separated into distinct categories as they are today. There were jewish christians and christian jews).

Around the same time that the christians were arguing in Constantinople, the scholars of this Persian religion living in the Fertile Crescent decided to transcribe their sacred tradition, recited from generation to generation for over a millennium or more. The book they compiled is known as the Avesta.

The Jews who were living in Mesopotamia already had a book: the Torah, the first five books of the bible. However, it would seem that they also joined in the discussions. While the Avesta was being put together, the Jewish rabbis compiled the Talmud, a set of commentaries on the Torah, often in response to issues raised by the mowbeds, the priests of the Avesta.

These were the three ‘religions of the book’. They shared many beliefs and values. For all of them, history has a beginning, and therefore also an end. The belief systems in India, further to the east, do not have this concept but rather one of endless cycles. There is a belief in one god (although the mowbeds who compiled the Avesta might say two: Ahura Mazda, the lord of light and Ahriman, the principle of evil or darkness). There was the concept of saviours, (prophets in Judaism) who brought new revelations to the human race. Zoroaster and Jesus were saviours. The three wise men who came from the east to visit the infant Jesus were magi, followers of Zoroaster. Some remembered Alexander the Great as a saviour. There were other, lesser saviours too. Later, some saw Abu Muslim, who was the focus of the overthrow of the arab Umayyad dynasty as a saviour.

This is the context in which the new religion of the Arabs arrived. It also had a prophet (Mohammed), a book (the Qur’an) and a timescale: the unbelievers had ‘an evil cradling’ awaiting them, whereas believers could look forward to dwelling in gardens underneath which rivers flow (phrases repeated many times in the Qur’an). And it most decisively had one god, recognised to be the same as  the god of the jews and the christians. By 800 CE the arabs living in the Fertile Crescent had also compiled their commentaries, collections of sayings of Mohammed not included in the Qur’an. These are known as the hadiths. The extent to which the hadiths were influenced by the ideas of the bishops, rabbis and mowbeds, exponents of the other religions of the book living in the same region, is too contentious to even start to explore.


The founding of Baghdad. 760-820, generations 439-441

The caliph chose the location, thirty miles upstream from the Persian capital of Ctesiphon, on the banks of the Tigris at the narrowest point between it and the Euphrates. Three astrologers,  an ex-Jew from Basra, an ex-Zoroastrian and a muslim, selected the date to start construction: 30th July 762. Three years later it was deemed officially finished, and forty years later it was the most populous city on the planet.

The layout of the central citadel was a perfect circle, as Persian capitals had been (including Ctesiphon before the arab armies destroyed it a century previously). To the locals this must have been, to all intents and purposes, the next incarnation of the Persian Empire.

There were two crucial differences, however. The man living with his harem in the citadel was not a shah but a caliph. And he adhered to the new religion of the arabs rather than the one that had dominated Persia for the previous two thousand years: zoroastrianism. He was a muslim, and as caliph he was the official successor of the Prophet who had died six generations earlier, in the year 632.

This meant that the zoroastrian priests were without a job. They had two thousand years’ worth of learning to draw on, and almost nobody to pass it on to. It wasn’t obligatory to convert to islam, but your career prospects at court probably got a boost if you did.

The muslims continued the Persian dedication to learning, however, and even expanded it. Under the Sassanid Empire (which fell to the arabs in 638) the main seat of learning had been the academy of Gundeshapur, a few hundred miles to the east. The caliph in Baghdad indicated that he was interested in promoting scholarship. Scholars from Gundeshapur relocated to Baghdad.

middle east 765 ad

Not only zoroastrians came to Baghdad. The largest christian church in the world at the time (in terms of geographical extent) had centres in Nisibis, a few hundred miles to the north, Merv in Khorasan to the east, and Gundeshapur. A century or so earlier the church in Constantinople started enforcing its orthodoxy more rigorously, and many christians moved to join the church of the East, whose headquarters were then in the sassanid capital of Ctesiphon. When the arabs sacked Ctesiphon in 641 the catholicos (equivalent of the pope in the latin roman church) moved north, nearer to Nisibis. Once Baghdad was established, the Church of the East relocated its headquarters there. In 780 the catholicos Timothy I was invited to meet the caliph, maybe because he had translated Aristotle’s ‘Topics’ into arabic, and maybe because the caliph wanted to discuss religion with him. Thus began a sometimes mutually profitable and sometimes uneasy relationship between the Church of the East and the caliphate that continued for several hundred years. In the good times christians were viziers, doctors and translators. In the bad times they were persecuted.

But on the whole the Church of the East thrived in the new abbasid empire as it had done with the sassanids. It already had missions further east, beyond the muslim empire into India and China. These were consolidated and confirmed. Five hundred years later, when the Mongols sacked Baghdad, the christian residents were spared from the slaughter because the khan’s wife and mother were both christians, members of the Church of the East.

The jews were there too, as they had been since the Babylonian captivity a thousand years before. When they had the chance to return to their homeland, many opted to stay in Mesopotamia. In the towns of Sura and Pumbedita, both on the Euphrates River, the definitive version of the Talmud, the commentary on jewish law, had been compiled, completed a century earlier.

The arabs, adherents of the newest religion in the region, were based at Kufa and Basra. In this period the arabic equivalent of the Talmud, the Hadiths, were compiled in these towns.

History books often aim for a tidy storyline, one that is simple, accessible and reasonable. But as each of us knows from our own experience, real-life events are not so tidy. I wonder how much, at the time, people saw a clear distinction between adherents of these four and the other religions swirling around the area. Other religions included the Manicheans (whom the arab scholars decided were not ‘people of the book’ and so liable to persecution), the Sabians (mentioned in the Qur’an but even a century after it had been written, it was forgotten who exactly they were), as well as other gnostic sects and Buddhists and Hindus from further east. Another important centre of learning at this time was Harran, not far from Nisibis. In order to escape the fate of the Manicheans, the inhabitants of Harran declared themselves to be the descendants of the Sabians.

How much did these educated people interact and influence each other? How many under-employed zoroastrian priests, jewish rabbis or christians offered a hand to encode the sayings of the prophet? Sura is only a few miles downstream from Kufa, after all.

Here is an example of the confusion. The abbasids had defeated the ummayads, the previous dynasty, around 750 with the help of a remarkable man. The man’s real name is not known, but he called himself Muslim abu Muslim ibn Muslim: Muslim, son of muslim and father of muslim. A pretty clear statement of one’s credentials, one would have thought. He launched his campaign in the town of Merv in Khorasan, a campaign to overthrow the ummayads and set a member of the Prophet’s family as caliph. The best candidate they had was a descendant of the Prophet’s uncle Abbas. Hence the abbasids.

Once installed, the new abbasid caliph had his own agenda, which did not include Abu Muslim. He invited him to dinner, and had him killed. This was not well received back in Khorasan. Several further insurrections against the abbasids were brutally put down by the caliphs’ armies.

But here is the curious bit. The rebellions were led by self-declared zoroastrians, who claimed loyalty to or discipleship from Abu Muslim. Our tidy narrative of different religions starts to feel somewhat frayed. If you want to investigate this further, two of those rebels were Babak Khoramdin and al-Muqanna.

One fact is indisputable however: Baghdad prospered. The translation movement, with help from scholars from all of the cities named here, went into a higher gear. The golden age of islam took off.

It must have been an exciting place to be. A delegation from India (maybe via Gundeshapur) brought their latest cutting-edge mathematics, systematised a century previously by the great mathematician Brahmagupta. This included the concept of zero as well as the decimal system of nine numbers and the sine function. The numbering system currently in use in this world was the Babylonian one of base-60, which lives on in our measurement of seconds, minutes and the degrees of a circle.

The Indians also brought the game of chess, which was then adapted to local tastes. Chess pieces look as they do today because they were depersonalised to avoid muslim sensitivities about depictions of the human form. The word ‘checkmate’ comes from the Persian ‘shah-mat’, ‘the king is dead’.

The first home-grown scientist of the golden age was Jabir ibn Hayyan, remembered as Geber the Alchemist, the founder of the science of chemistry. He probably lived in Kufa and almost certainly spent time in the new Baghdad. He wrote prolifically. He developed theories of what matter is made of, partly based on received learning and part on his own researches. He advocated experimentation as a way to learning. However, much of his writing was so obscure that the word ‘gibberish’ was coined a few centuries later, meaning ‘as impenetrable as the works of Jabir’.


The blackbird comes to Cordoba. Generations 442-443, 820-860

He is remembered as the blackbird, el pajaro negro, in Spain to this day. He is credited with introducing the lute, toothpaste, deodorant, tablecloths, glass tableware and the three-course meal to the court at Cordoba, as well as asparagus, a new hairstyle and seasonal fashions. He was reportedly a composer who memorised 10,000 songs himself and was the founder of a music school.

The legends continue. He is said to have designed a new, lightweight style of lute with an extra, fifth string. The first four strings were said to symbolise the four humours. This new fifth string, he is reported to have said, represented the soul.

His name was Abu al-Hasan ‘Ali ibn Nafi’. He was born around 789 somewhere in the middle east. Persia, Kurdistan and Mesopotamia have all been suggested. The accounts agree that he studied music in Baghdad as a young man. They also agree on his nickname, Zaryab or Ziryab, but not its meaning or origin. Does it come from the arabic word for blackbird, shahrur, or from the persian words for liquid gold, zar ab? This is a political minefield that I prefer not to enter. In Baghdad the religion came from the arabs but a large part of the civilisation came from the persians, so there was probably a degree of tension between the two cultures.

The accounts all agree that he was forced to leave Baghdad, but the reasons given vary. Was it political exile after the civil war between the caliph al-Amin and his brother al-Mansur? If he was a protege of al-Amin it would have been prudent to make himself scarce after al-Mansur took over. The story told by ibn Khaldun several centuries later was that he excelled his music master, who became jealous and paid him to leave. However, that story had been told before, about a musician at the Persian court a couple of centuries previously. Maybe it was too good a tale to waste.

It is agreed that he travelled across north Africa, and spent some time at the court of the emir Ziyadat Allah I in Ifriqiya, modern Tunisia. From there he was invited to Cordoba. The emir who had issued the invitation, al-Hakam, was dead by the time he and his family arrived in 822, but al-Hakam’s son and successor, Abd al Rahman, upheld it. He was given a villa in the city, land in the countryside and a stipend of 200 gold pieces per month, guaranteed for thirty years.

Ziryab repaid Abd al-Rahman’s investment. He systematised the study of music and founded a conservatoire. His teaching methods were replicated across north Africa. The styles of music he explored, combining middle eastern traditions with the indigenous music of al-Andalus, are the basis of a large part of the musical traditions in Spain and north Africa to this day.

He is also remembered for his contributions to civilised city living. He made it popular for men to be clean-shaven and for women to have short hair with a fringe on the forehead (US: bangs). He invented a soap with rosewater and salts. He introduced seasonal fashions: fresh colours in spring, white in the heat of the summer, fiery reds and yellow in autumn and dark, warm furs in winter.

At the table, he replaced the traditional metal drinking goblets with drinking vessels of crystal. He is credited with inventing the leather tablecloth and the three-course meal of soup or starter, followed by a main course and finishing with a dessert or nuts. This latter was a completely new invention. Not even Baghdadis had three-course meals. Many dishes are named after him. It is possible that the Indian sweet dish, the jalebi, derives its name from Ziryab.

He invited other learned men from his homeland. Indian visitors brought the game of chess. He invited doctors and astrologers from elsewhere in the arabic-speaking world to come to Cordoba to share their learning.

He died in 857. His children continued his work. One of his daughters married the court vizier. His legacy is fondly remembered in Spain.


A christian and a muslim playing lutes, cover of the cantigas de santa Maria by Alfonso el Sabio, king of Toledo, 13th century.

The heyday of the House of Wisdom, 820-860, generations 442-444

This was the time when Baghdad was the most exciting place to be, if you were a person who was interested in new ideas, in pushing back the envelope of human understanding. Philosophy, mathematics, astronomy, geography, engineering – all were explored and developed here.

Mathematics was further developed as a tool to make sense of the world. Algebra was invented (the system of balancing the sides of an equation to find the value of an unknown, usually described as ‘x’). This, we non-mathematicians may not realise, is a powerful tool indeed. As are five of the six trigonometric functions, the names of which I remember from school. The sine was brought from India. The others (cosine, tangent, secant, cosine, cosecant, cotangent) were developed in Baghdad in this period. The Indian numbering system that we still use, of nine digits and a zero, was promoted and explored.

The practice of philosophy, of studying how to think about the human situation, was brought into the modern monotheistic world from that of the Greeks.

Engineering techniques (the valve, the crankshaft, feedback controls) were rescued from the ancient world, understood, refined and applied in new ways.

banu musa lamp

This drawing for a self-trimming lamp is one of a hundred entries in the Book of Ingenious Devices by the Banu Musa brothers. The book also contains instructions and the design for a water-powered musical instrument, a concept not attempted again for a thousand years.

The Banu Musa brothers, as well as the multi-talented al-Kindi (known as the father of arabic philosophy) and the extraordinary mathematician al-Khwarizmi, were all employed in the House of Wisdom, the Bayt al-Hikma.

Their employer was the caliph al-Mamun.

How did this all come together? A combination of factors. Here are some of them, in no particular order.

The first paper mill opened in Baghdad in 795. The technology of paper-making was as profound in its significance as the development of the printing press in renaissance Europe or the internet in our own lifetimes. While northern Europeans used scraped animal skins to write on, educated Baghdadis had libraries with hundreds or thousands of books.

Baghdad itself was located at the meeting point of the Persian and Indian cultures to the east and that of the Mediterranean (particularly Greece) to the west. There is a long history of cultural exchange between India and Persia. Baghdad had been built 50km north of the ancient Persian capital of Ctesiphon. Indian mathematicians and their ideas were welcome in Baghdad.

The religion of the rulers, islam, was tolerant of (most) other faiths. Christians, Jews and Zoroastrians had to pay a poll tax but were otherwise largely left to pursue their own beliefs. In fact the administration sometimes preferred them not to convert to islam. Mass conversion meant a drop in tax revenues. As Constantinople was pursuing a less tolerant line to unorthodox christianity at the time, many non-mainstream christians found it healthier to live in the muslim world. They brought ancient Greek texts with them, and could read them.

The schools of Athens and Alexandria, with a continuous tradition of learning going back to ancient Greece, had been closed a century or so earlier.

Islam values literacy. The Quran is to be read and recited, in arabic.

Arabic was the common language from Cordoba in the west to Kabul in the east. Some said that they found it easier to express the new ideas in arabic than their native language. It was the language of learning, as latin was in the medieval world and English is now.

The translation movement had been in progress for some time. As well as Indian mathematical texts, Greek medical, scientific and medical texts were brought to Baghdad and translated into arabic. Translators were well paid for their work, sometimes the weight of the finished book in gold. Not only the caliph, but many of the elite joined in the search for ancient texts to translate. It is said that a condition of a peace treaty between Baghdad and Constantinople was that a copy of Ptolemy’s Almagest should be made available to Baghdad. To understand these texts well enough to be able to translate them, advanced knowledge of the subject is required. This then facilitated a comparison of the different traditions. Where do Greek geometry and Indian mathematics coincide, for example?

The culture of Baghdad was one of exchange, of ideas as well as goods. The Prophet himself had been a trader. There was a stable administration. Recently, a written cheque has been found which was issued in Baghdad and cashed in Cordoba. Baghdad became rich.

There were tensions, too. The differences of view about the human’s relation to God came into sharp focus. This is the time when the hadith, the sayings of the Prophet, were collected and catalogued. The ulama, the imams, theological scholars, valued the Quran and the hadith above any discoveries by the philosophers and scientists. Some of the points of contention: Was the Quran created at a moment in time, or as it is directly revealed from God is it co-eternal with God? The caliph and the scholars of the House of Wisdom thought the former, the scholars of the ulama thought the latter. Does a person find the way to God via reason, working it out, or inspiration, faith, devotion?

Caliph al-Mamun was an advocate of reason over revelation. He loved the inquiry, the finding it out. (Among other projects, he despatched his scholars to measure the size of the Earth. Ptolemy had given an estimate in the Almagest, measured in stades, but nobody knew what a stade was.) Towards the end of his life al-Mamun issued a decree that the Quran was created. As he was caliph and therefore successor to the Prophet, he declared himself authorised to make such a pronouncement. Any imam who disagreed with him was to be punished. This was a dangerous precedent for the ulama, who saw themselves as the ones best qualified to interpret the wisdom of islam.

Inevitably this hardening of positions led to the creation of heroes and martyrs in those who resisted the caliph. Fifteen years after his death in 833 the decree was revoked and the pendulum began to swing in the opposite direction. The scholars of the House of Wisdom went elsewhere.

Divisions in the Golden Age. Generations 445-447, 880-940

At the start of this period the largest, most influential and probably the richest city in the world was Baghdad. It was just over a century old, having been established in 762, but it was a magnet for scholars, attracted by its libraries of works translated from Greek, Syriac, Sanskrit, Persian and Chinese.

arabesque Samarra

The arts flourished too. This decorative panel is from Samarra, north of Baghdad and is one of the first appearances of the style now known as ‘arabesque’.

In this post I will focus on two men, both of whom lived in Baghdad. Both were highly accomplished and they came to very different world views.

The first was called Abu Bakr Muhammad al-Razi. He was born in Rayy (Razi) in Persia in around 860. Rayy is now a suburb of Tehran. He seems to have been a kind, clever and open-minded man, the sort of person you would feel richer for knowing.

As a young man al-Razi studied music, mathematics and philosophy, among other subjects. He was particularly renowned for his investigations into chemistry. However, his writings from his early life are now mainly known from quotes by later writers such as al-Biruni and Ibn Sina as the original documents have been lost.

Around the age of 30 he went to Baghdad, about 600 miles away. He studied medicine with Ali ibn Sahl, a famous physician of the city. (Ibn Sahl was a convert from Judaism. His father had translated Ptolemy’s Almagest into Arabic.) It is said that al-Razi soon surpassed his teachers. Around the year 900 the caliph al-Muktafi commissioned him to set up a hospital.

To select a site, he had pieces of fresh meat hung up outside at different places in the city. After a few days he checked each of them. The piece of meat that had shown the least putrefaction was deemed to be in the healthiest location, and that is where the hospital was built.

The hospital itself had a psychiatric ward as well as medical and surgical wards. There were baths for men and for women. It was organised as a series of circles. The most straightforward ailments were dealt with in the outer circle. Al-Razi himself looked after the inner circle of most difficult cases.

He kept copious records and wrote extensively. He even questioned the authority of Galen, the main reference for medicine in his world and in the west until the Renaissance. He questioned Galen’s theory of the four humours when he observed that the body of a patient who drinks a hot drink warms up by more than the temperature of the drink itself, suggesting that more is going on than the simple transfer of warmth.

He is the first person known to have used a control group in a medical trial. He divided  a group of people showing the symptoms of meningitis into two subgroups. To one group he applied bloodletting and he left the other alone. He reported that the group who received bloodletting fared better than the control group.

He wrote a book on medical ethics. He said, “The doctor’s aim is to do good, even to our enemies, so much more to our friends…”. He acknowledged that some diseases, such as advanced cancer or leprosy, are incurable. He also acknowledged that untrained healers, including wise women, were often more successful in treating certain diseases than trained physicians like himself. He wrote a medical self-help book.

Al-Razi’s open-mindedness extended to religion, too, and that got him into trouble. For him, God has given humans the ability to think for themselves. To unquestioningly accept the dicta of a revealed religion would be an affront to this God-given ability.

I really like this man.

The other influential man of this period took a different view. Abu al-Hasan al-Ashari was born in Basra, south of Baghdad in 874. Until he was forty he probably would not have disagreed too much with al-Razi. Then it is said that he had three life-changing dreams. In these dreams Mohammed commanded him to adhere to tradition, which he took to mean the Quran and the collected sayings, the Hadith.

As a young man he had studied philosophy and engaged in the debates of the time. As so much had been translated over the previous century, many of the discussions revolved around integrating the wisdom of the ancients with the revealed religion of Islam.

The first pillar of Islam requires the adherent to attest to the unity of God: ‘There is no God but God, and Mohammed is his messenger’.

To me, that sounds fairly straightforward, but the scholars went into contortions over it. Is the Quran separate from God or, as it is God’s words, is it therefore part of God? Does God know everything, down to every flap of a butterfly’s wing? Where is human free will? Has the universe existed forever or was it created at a certain moment?

Islam is a practical religion. It is based on action rather than beliefs as is the case with christianity. All of the five pillars are actions. The first pillar is known as the shahada, which is translated as the attestation, the bearing witness. In other words, an action. There were debates about how to behave, what to do, and people looked to the Quran and the Hadith for guidance. Al-Ashari had been trained in the mental gymnastics of the philosophers, so when he joined the traditionalist camp he was well-prepared to engage the philosophers with their own tools.

For al-Ashari the focus became to know God better. The Quran was the word of God and so part of God and so eternal and uncreated. It was to be taken literally rather than metaphorically. When it talked of God’s hands or eyes, it meant that God has hands and eyes. To al-Ashari’s credit, he didn’t think that everything was understood. He believed that there was always room for improvement, so he didn’t think that the scholars had the final word yet. Although he declared that God is omnipotent, he found a way to incorporate free will (which I confess is too subtle for me and so I won’t go into it). He is remembered as one of the foremost sunni theologians.

Al-Razi had probably gone back to Rayy to set up a hospital there when al-Ashari moved to Baghdad. I don’t think they would have had much in common if they did meet.

And on a completely separate issue, the first reported use of the decimal point dates from the end of this period.  The Book of Chapters of Hindu Arithmetic by al-Uqlidisi (literally, ‘the Euclidean’) was written in Damascus. He set a problem of calculation to which the answer was 179.685, which he wrote as 179’685. More to follow on the Indian contribution to mathematics as we go on …