This chapter chronicles the rise of Chinggis Khan and the history of the Mongols in the Middle East. The Mongol army was not a standard nomad army; it was not tribally organized, contained a number of settled soldiers, and was strictly disciplined. In describing the conquest of Iran, the chapter emphasizes the role of Iranians and the importance of local Iranian politics during the conquest and early Mongol rule. It argues that the Mongols were not ignorant of the value of city life and agriculture, and that the abuses of taxation and extortion described in the chronicles impoverished Mongol nomads as well as agriculturalists. In examining acculturation, one should look beyond the court, to the interactions of Mongols and Iranians within the army and in regional politics. Finally, the chapter considers the cultural impact of the Mongols, both their brilliant court culture and the result of their rule in the division of the Middle East into three spheres: Turkic, Arab, and Iranian.