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 the Roman Emperor’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 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’.


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 …



Generations 451-452, 1000-1040. Airbrushed from history

This period saw the work of three extraordinary men, and my school history lessons told me nothing about them.

One of the men was one of the most influential philosophers of the islamic world. His updating of the ideas of Aristotle was to influence christian, jewish and muslim thought for the next few hundred years. He also wrote a medical encyclopedia that was the standard text in Europe and the islamic world for the next half-millennium.

Another was a renaissance man four centuries ahead of his time. His wide-ranging interests included anthropology, pharmacology and mineralogy. He devised a way to measure the circumference of the Earth, which he did to an accuracy of within two hundred miles.

The third can be reasonably described as the founder of the scientific method. He established the practice of developing a hypothesis and using reproducible experiments to test it, to verify or disprove it. He was called ibn al-Haytham, and will be the subject of the rest of this post.

He was born in Basra in what is now Iraq in 965. He moved to Egypt in the early 1000’s  and stayed there for the rest of his life. He died in about 1040.

Caliph al-Hakim of Egypt had established a university in Cairo in 1004, and supplied it with a huge library, known as the House of Knowledge or Dar al-Hikmah in arabic. He so wanted to encourage learning that access was open to all and free pens, ink and inkstands were available to those who studied there. Ibn al-Haytham already had a reputation as an impressive thinker, and as he lived in the interconnected arabic-speaking world, he was invited to join the academic community in Cairo, over 1500 miles away.

He was asked to investigate damming the River Nile, in order to regulate the regular devastating floods. On arrival, he soon came to the conclusion that the project was beyond any technology at his disposal. This presented a problem. Caliph al-Hakim did not have a reputation for stability when things didn’t go the way he wanted. One of his nicknames, which was almost certainly not said to his face, was the mad caliph. He once ordered all the dogs in Cairo to be killed because their barking bothered him. Rather than bring the bad news to the caliph, Ibn al-Haytham decided to feign madness himself.

For this he was put under house arrest in Cairo, which turned out to be a blessing in disguise. He had the resources of the new university and its enormous library nearby, and space to think his own thoughts. One of the subjects he addressed was optics. The ancient Greeks had attempted descriptions of the way humans see things. Plato and Euclid had proposed that rays travel out from the eyes towards the object we look at, and then bring the visual information back to the eye. Ibn al-Haytham raised a simple objection to this: in that case, why does it hurt our eyes when we stare at the sun?

Instead, he proposed another hypothesis, that the eye is able to receive light rays that come from the object, and to translate the information they bring into a visual image. He proposed that light rays travel in straight lines from the distant object to the eye. Others had pondered along these lines, but he then went a further, pioneering step. He set up repeatable experiments to test his hypothesis, and documented them. He looked through a straight tube to show that the light from the object travels in a straight line. He set up a pinhole camera, and placed a candle in front of it. He demonstrated that the light from the top of the candle travels through the pinhole to the bottom of the receiving chamber, and light from the bottom of the candle travels through the pinhole to the top. And so the image appears upside-down. Not only did he record his results, he set up ways for others to test and verify or disprove them.

book of optics eye

A diagram of the eye from Ibn al-Haytham’s Book of Optics. 

He championed enquiry, not taking other people’s word for it (no matter how eminent they are), and relying on one’s own investigations. And so Ibn al-Haytham is considered by many to be the founder of the scientific method.

As well as optics and engineering he wrote on astronomy, philosophy, theology and more. Even number theory. One hypothesis he put forward about prime numbers was finally proven to be correct by the Swiss mathematician Leonhard Euler, eight hundred years later. A geometrical problem he proposed was solved algebraically in 1997.

When his writings were translated into latin and became accessible to the west, his name was latinised as Alhazen. In the thirteenth century the English scholar Roger Bacon and the Polish philosopher Erazmus Witelo wrote extensively on optics after reading his books in translation.

“The duty of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and,.. attack it from every side. He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency.”

And until I started researching for this blog I had never heard of him.

PS The physicist Jim al-Khalili named these three men as the greatest muslim scientists of all time and among the top ten in the world. Here is a link to his presentation to the Royal Society explaining why.