Who ruled Baghdad?

Baghdad lies on both banks of the Tigris in central Iraq, at the point where the Tigris and Euphrates run closest together and canals could link the two. The region had been the heartland of Babylon, Seleucia and the Persian capital Ctesiphon, all within a short distance of the site. Baghdad itself was a planned imperial foundation of the eighth century, and for five hundred years it was the seat of the caliphs and one of the largest and most learned cities on earth. Its later history is marked by sackings, foreign rule and, in recent decades, war.

A village called Baghdad existed before Islam, but the city dates from 762 CE, when the Abbasid caliph al-Mansur chose the west bank of the Tigris for a new capital of the Abbasid Caliphate. He built a circular walled city, about two kilometres across, with the caliph's palace and great mosque at its centre and four gates facing the corners of the empire. Markets and suburbs quickly spread beyond the walls and across the river. By the time of Harun al-Rashid, who reigned from 786 to 809, Baghdad was perhaps the largest city in the world outside China, with several hundred thousand people.

Its wealth supported an extraordinary intellectual life. Scholars translated Greek, Persian and Indian works into Arabic, and the institution known as the House of Wisdom became a symbol of the age, with mathematicians such as al-Khwarizmi working in the city. Paper mills, booksellers, hospitals and observatories made Baghdad the centre of the Islamic golden age.

Political troubles came early. A civil war between Harun's sons left the Round City damaged in 812 and 813, and the caliphs moved their court to Samarra from 836 to 892. From 945 the Persian Buyid dynasty held real power in Baghdad, leaving the caliph only religious authority, and in 1055 the Seljuk Turks replaced them. The caliphate recovered some independence in the twelfth century, but in 1258 the Mongols under Hulagu took the city in the siege of Baghdad, killed the last Abbasid caliph and massacred a large part of the population. Baghdad became a provincial town of the Ilkhanate.

Tamerlane sacked the city again in 1401. It then passed among Turkmen dynasties and in 1508 to Safavid Persia, before Suleiman the Magnificent took it for the Ottoman Empire in 1534. The Safavids recaptured it in 1624 and lost it for good in 1638. For much of the eighteenth century Baghdad was governed by a line of Georgian Mamluk pashas with wide independence, until in 1831 a flood and an outbreak of plague devastated the city and the Ottomans restored direct rule. Reforming governors later in the century brought newspapers, schools and a tramway.

British forces captured Baghdad in March 1917. It became the capital of the British-mandated Kingdom of Iraq under Faisal I in 1921, and of an independent Iraq in 1932. The city then had a large Jewish community, nearly all of whom emigrated after the anti-Jewish riots of 1941 and the creation of Israel. The monarchy was overthrown in 1958, and under the Ba'ath regime, and especially Saddam Hussein, oil money paid for new boulevards and monuments. The Iran-Iraq War, the Gulf War of 1991 and a decade of sanctions wore the city down, and in 2003 American-led forces captured it. Years of insurgency and sectarian killing followed, peaking in 2006 and 2007 and dividing many neighbourhoods along religious lines.

Baghdad today is Iraq's capital and by far its largest city, with a population of more than seven million.