This post follows on from the previous Abbasid post Brothers up in Arms. It was originally written as one post but I felt it was a bit long so cut it in half and will conclude the life of the caliph Mamun here.
At the end of the last post we left the caliph Mamun back in control in Baghdad and engaged in reconciliation and rebuilding following the civil war with his brother and his failed attempt to rule the caliphate from distant Merv. In 821 an opportunity presented itself for Mamun to interfere in affairs in Byzantium with the appearance in northern Syria of Thomas the Slav, who was leading a rebellion against the incumbent emperor Michael II. Thomas' emissary to the caliph was sent with extravagant promises to make. Allowing for propaganda intended to blacken his name as a traitor to the empire, Thomas is variously credited with signing away frontier provinces or perhaps even undertaking to en-fief the entire empire to the caliphate in exchange for an alliance which would safeguard his rear whilst he turned his forces against Constantinople. The caliph accepted with alacrity and provided Thomas with a substantial contribution to his war chest. The rebel was even permitted to celebrate his coronation as Emperor of the Romans in the city of Antioch. Mamun would have been advised to remain sceptical of the bargain. Thomas, after all, was not the first Byzantine rebel commander to promise much and deliver nothing.
Thomas the Slav arrives in Syria - Madrid Skylitzes
By 826 Mamun had regained a firm grip on his territories with Syria and Egypt having been entirely pacified by the son of Tahir and returned to obedience. The rebellion of the Khurramites was still ongoing but the tide seemed to be turning. In 830 an army of Khurramite rebels holding out in the Zagros Mountains of western Iran led by a Persian nobleman by the name of Nasr was heavily defeated by the Caliph’s forces. Seeing the writing on the wall for the Khurramite cause, Nasr chose to lead his surviving troops through Armenia out of harm’s way and sought refuge within the Byzantine Empire.
The arrival of Nasr with some fourteen thousand armed followers who professed themselves willing to fight for the empire against the caliphate was greeted rapturously by the new emperor Theophilus, who had succeeded his father Michael II in 829. The new arrivals were given land and incorporated into the Byzantine military under the command of Nasr himself, upon whom the emperor bestowed Patrician rank. Nasr and his followers agreed in principle at least to embrace Christianity and were baptised. Nasr now took a new Christian name and became Theophobos. As Christians, the former Khurramites were now permitted to marry and Theophobos was given the emperor’s own sister-in-law as a bride. The fugitive rebel had landed on his feet.
Embassy from Theophilus to Mamun - Madrid Sylitzes
Good relations had previously been established between Theophilus and Mamun but this provocation was too much for the caliph, who decided that the time had come to lead an expedition against the infidel as his father had done. In the summer of 830 he launched a limited invasion of Anatolia, with his son Abbas also leading a column. Little was achieved aside from symbolism but in the following year Theophilus retaliated against the raid by invading Muslim held Cilicia and sacking Tarsus. Elated by his success, Theophilus returned to Constantinople and celebrated with an elaborate triumphal procession followed by races in the hippodrome in which he himself participated. Mamun meanwhile had retired to Damascus. The first Abbasid caliph to visit the city, he was making a point of showing his face in recently re-pacified Syria. Retaliating in turn to Theophilus’ campaign, Mamun once more led his forces across the border and captured the town of Heraclea, which his father had also successfully taken in a much celebrated victory.
In 832 a tenuous peace was negotiated between the two empires whilst Mamun, who must have been the most well travelled of all the caliphs, decided to visit Egypt and show his face there too. Whilst in the land of the pharaohs, the ever curious caliph decided to investigate the pyramids and had an exploratory tunnel dug into the side of the Great Pyramid. This tunnel intersected the interior passages within the pyramid and the caliph was able to venture inside and make his way up to the burial chamber of Khufu, only to find the sarcophagus empty and the tomb looted in distant antiquity.
With his Egyptian efforts frustrated, the caliph set out once again in the summer of 833 in what promised to be a more sizable campaign against the Byzantines. As he relaxed beside a stream during his advance from Tarsus however, the caliph suddenly took ill and his fever soon proved fatal. He had named no successor, realising perhaps the futility of such actions. His younger brother Qasim, who had been appointed third in line in the provisions of their father Harun al Rashid, moved swiftly to seize the reins of power as caliph Al-Mutasim. Mamun was laid to rest in Tarsus and his tomb survives to this day.
In overall assessment Mamun, for me at least, emerges as a more impressive figure than his more famous father Harun al Rashid. He had shown himself a good judge of character in the men he had chosen to trust and had displayed a willingness to accommodate, reconcile and compromise in his policies and his exercise of mercy where possible. He was nevertheless prepared to be utterly ruthless when a change of policy demanded it. He was, above all, a pragmatist.
Muslim scholars discuss the use of the astrolabe
Mamun’s greatest legacy is as a patron of scientific enquiry. Whereas almost every anecdote about Harun seems to involve dancing girls and drunken poets, Mamun appears to have taken a serious interest in the scholarship being pursued in Baghdad under the auspices of the caliphs. The institution that would come to be known as the Bayt al-hikma or House of Wisdom was first established in Baghdad under the auspices of Mansur as a safe repository for his growing collection of scientific and philosophical manuscripts. This is imagined as a centrally organised and officially controlled research facility but in truth no such control or organisation existed and individual scholars carried out their work independently with funding from wealthy patrons amongst the caliphs' nadim. The term House of Wisdom is better thought of as an idea or a movement at this point in history rather than a place. The effort to translate works from Greek, Indian and Persian into Arabic had been given particular impetus by the Barmakids. Yahya the Barmakid is said to have commissioned the first Arabic translation of Euclid and he and his sons numbered many pet scholars amongst their clients.
Mamun of course was raised as the protégé of Jaffar the Barmakid and perhaps gained his eager curiosity and love of scientific enquiry from the scholars patronised by Jaffar. Under Mamun’s caliphate the pursuit of scientific knowledge received a massive boost from the personal interest that the caliph took in such matters. Mamun made enquiries as to his scholars’ needs and progress, sourced new manuscripts and scientific instruments during his visits to Damascus and Egypt and oversaw the construction of a new observatory in Baghdad. Stepping into the shoes of the Barmakids came three brothers known as the Banu Musa who had accompanied Mamun westwards on his return from Khurasan. Like the Barmakids they were an old Persian family, wealthy, cultured and well connected. Working for the Banu Musa, a good translator could earn five hundred dinars a month and they assembled an army of them.
Foremost of all the scholars of Baghdad during Mamun’s reign was Muhammad ibn Musa Al-Khwarizmi. This great polymath was another who had made his way westwards from Khurasan to the City of Peace. His contribution to modern mathematics, astronomy and geography is formidable. Even the Western corruption of his name is preserved in the term algorithm. Al-Khwarizmi was responsible for the production of three great works of translation and further scholarship, whose transmission to the west have cemented his reputation as the greatest of oriental sages. The first was a distillation of all Indian mathematical and astronomical knowledge which had been transmitted to the Arab world within a corpus of work called the siddhanta. To this Al-Khwarizmi added star tables known as the zij al sindhind whose accuracy would be unsurpassed for centuries and the earliest known description of the use of the astrolabe. Al Khwarizmi also needed to include an explanatory treatise on the Indian system of calculation using the numbers 1-9 along with the concept of zero.
Muhammad ibn Musa Al-Khwarizmi
If like me you hated maths at school then you have reason to curse Al-Khwarizmi for his next work; the book of restoring and balancing, Kitab al jabr wa’l-muqabala, from which we take the term algebra. The book detailed the use of equations in solving the problems of the day; calculating tax or inheritance, partitioning land and regulating trade. His third great work the al-majisti was a translation and commentary on the works of Ptolemy, known as the Almagest in the West.
Upon perusing the Almagest, Mamun demanded a practical demonstration of the theory within. In a study commissioned by the caliph to determine the accuracy of Ptolemy’s estimate of the circumference of the Earth, a party of astronomers set out into a flat area of desert and measured the altitude of the pole star. Driving a pole into the ground they fixed a piece of cord of known length to it and then walked north in a straight line, taking measurements of the altitude of the pole star as they went, driving in more posts and running out the cord behind them. Once they had reached a point at which the altitude of the pole star had risen by one degree, they retraced their steps along the posts they had driven into the ground and measured their distance travelled from the length of cord they had paid out. I can only assume that someone was following on behind on the way out to recycle the cord already used, unless they were carrying 66 miles of cord with them, for that was the measured distance travelled; 66.6 miles to be precise. Proceeding south from their original start point they then continued until they had covered the same distance at which point they observed that the altitude of the pole star was one degree lower than at their start point. The entire experiment was then repeated in a second area of desert and the measurements found to be the same, at which point the caliph declared himself satisfied with their observations. The distance corresponding to a degree of latitude was found to be 32.2 farsakhs or 66.6 miles. From this it was concluded that the circumference of the Earth was eight thousand farsakhs, or 24,000 miles, impressively close to the modern figure.
Such was the standard of intellectual enquiry taking place on Mamun’s watch. It would be three centuries before anyone in the West even started to catch up. None of his successors would match his passion but the touch paper had been well and truly lit and would continue to burn brightly.
Mamun and the pyramids
Mamun and the pyramids