The Round City: Baghdad, 762
The Islamic Golden AgeA Caliph Who Needed a River
Abu Jafar al-Mansur became the second Abbasid caliph in 754, and he did not trust the cities he had inherited. Kufa was full of men who had backed the revolution and expected to be repaid in influence. So he went looking for ground of his own, and chose a stretch of Tigris bank where Sasanian canals still tied the river across to the Euphrates — an irrigation grid dug by the empire the Arabs had conquered a century earlier, and simply inherited. The geographer al-Yaqubi, writing a century later, has him at the water's edge saying nothing lay between this bank and China: whatever the sea carried could reach his door. He named the place Madinat al-Salam, the City of Peace. It stayed the official name for centuries — it is what the coins say — but it never won ordinary speech. The name that stuck, Baghdad, was not Arabic and probably not new — it seems to have belonged to a village already on the site.
The Hour, and the Problem With It
The first brick was not laid when the builders were ready. It was laid when the sky was judged right. Al-Mansur used a team of astrologers, of whom two names always survive: Nawbakht, a Persian convert from Zoroastrianism, who led them, and Mashallah ibn Athari, a Jewish astrologer of Khurasani family working out of Basra — and their craft, electional astrology, was itself an import, assembled from Greek, Persian and Indian material Arabic was still busy absorbing. They picked a moment with Jupiter rising in Sagittarius, usually dated 30 July 762, though al-Yaqubi puts the start of work a few days later, on 2 August, and the two have never been reconciled. Then the harder problem: the horoscope reaches us through al-Biruni in the eleventh century and Yaqut in the thirteenth. Nothing written at the time survives to check either against.
A Plan Nobody Has Ever Stood In
The design was concentric: a moat, brick walls, and four gates set at equal intervals, each named for the road that ran out of it — the Kufa gate, the Basra gate, the Syrian gate, the Khurasan gate. Four arcaded avenues drove inward to a wide cleared space holding almost nothing but the congregational mosque and the caliph's palace, topped by a dome the sources call green, eighty cubits high, with a horseman on its summit. None of that is measured. Estimates of the diameter run from about two kilometres to over two and a half. The descriptions come from al-Yaqubi a century afterwards and al-Khatib al-Baghdadi three centuries afterwards, and the tidy plan printed in every book is a modern reconstruction — Herzfeld, Creswell and Lassner each drew a different city from the same sentences.
A Hundred Thousand Workers, and a Number That Will Not Behave
Al-Yaqubi says the caliph wrote to every province for anyone who understood building, and would not break ground until a hundred thousand workers and craftsmen had gathered. Al-Tabari preserves what they earned: a master mason took a qirat a day — a small fraction of a dirham, though the sources do not fix which fraction. Al-Tabari also gives a total outlay of just under five million dirhams, while other chroniclers report a hundred million dirhams, or eighteen million gold dinars. The silver figures alone differ twentyfold, and the gold total is wider still once converted. That is not an arithmetic slip; it means these are impressions, not ledgers. Some of the material was meant to be second-hand: al-Mansur began pulling down the Sasanian palace at Ctesiphon for its brick, and gave up when hauling old brick upriver proved dearer than firing new. The chroniclers wrap that in a set-piece — his adviser Khalid ibn Barmak objects, is told he is thinking like a Persian, and is overruled, then tells the caliph to finish what he started so nobody can say he failed to level what a Persian king built. The scene survives in more than one version, including one in which Khalid stops the demolition before it begins. The salvage is well attested; the dialogue is a story told about it.
The Circle Did Not Hold
Within roughly a decade the markets were expelled to Karkh, outside the walls. Al-Tabari gives the practical reason — strangers sleeping inside the gates who might open one at night — and also records a story, that a Byzantine envoy taken onto the ramparts said he saw a splendid city, and saw the caliph's enemies living in it: the traders. Al-Mansur was already building across the river for his son. In 836 the caliphs left for Samarra, and on returning did not move back into the circle. On the night of 9 March 941 the Green Dome fell in a rainstorm. The city around it kept swelling — within a century probably the largest on earth outside China, though modern estimates of its population run from roughly a hundred thousand to over a million, which is a confession rather than a figure. Of the circle, nothing stands.
Key Dates to Remember
- 754 — Al-Mansur becomes the second Abbasid caliph, four years after his family takes power, and begins looking for a capital he can hold.
- 30 July 762 — The hour elected by the astrologers Nawbakht and Mashallah ibn Athari. Al-Yaqubi dates the start of work to 2 August; the accounts have never been squared.
- 766 — The Round City is reported finished, about four years after the first brick.
- 775 — Al-Mansur dies. The capital has already outgrown his circle, with building underway across the river.
- 9 March 941 — The Green Dome over the caliph's palace collapses in a night rainstorm, taking its horseman with it.