In the early thirteenth century the Mongols arrived in the Middle East. Originally from the grasslands of Mongolia, in 1206 they proclaimed Chinggis Khan (ca. 1162–1227) as their leader, and he welded Mongol, Tartar, and Turkish tribes into a strong confederation that rapidly subdued neighboring settled societies (see “Chinggis Khan and the Mongol Empire” in Chapter 12). After conquering much of north China, the Mongols swept westward, leaving a trail of blood and destruction. They used terror as a weapon, and out of fear many cities surrendered without a fight.

In 1219–1221, when the Mongols first reached the Islamic lands, the areas from Persia through the Central Asian cities of Herat and Samarkand were part of the kingdom of Khwarizm. The ruler — the son of a Turkish slave who had risen to governor of a province — was a conqueror himself, having conquered much of Persia. He had the audacity to execute Chinggis’s envoy, and Chinggis retaliated with a force of a hundred thousand soldiers that sacked city after city, often slaughtering the residents or enslaving them and sending them to Mongolia. Millions are said to have died. The irrigation systems that were needed for agriculture in this dry region had been neglected for some time, and with the Mongol invasions they suffered a fatal blow.

Not many Mongol forces were left in Persia after the campaign of 1219–1221, and another army, sent in 1237, captured the Persian city of Isfahan. In 1251 the decision was taken to push farther west. Chinggis Khan’s grandson Hülegü (1217–1265) led an attack on the Abbasids in Baghdad, sacking and burning the city and killing the last Abbasid caliph in 1258. The fall of Damascus followed in 1260. Mamluk soldiers from Egypt, however, were able to withstand the Mongols and win a major victory at Ayn Jalut in Syria, which has been credited with saving Egypt and the Muslim lands in North Africa and perhaps Spain. At any rate, the desert ecology of the region did not provide suitable support for the Mongol armies, which required five horses for each soldier. Moreover, in 1260 the Great Khan (ruler of Mongolia and China) died, and the top Mongol generals withdrew to Mongolia for the selection of the next Great Khan.

Hülegü and his descendants ruled the central Muslim lands (referred to as the Il-khanate) for eighty years. In 1295 his descendant Ghazan embraced Islam and worked for the revival of Muslim culture. As the Turks had done earlier, the Mongols, once converted, injected new vigor into the faith and spirit of Islam. In the Il-khanate the Mongols governed through Persian viziers and native financial officials.