Rashid al-Din Hamadani's (d. 718/1319) Jami? al-tawarikh has been described by many as the first world history ever. Composed in Persian for the Mongol Il-khans Ghazan (r. 1295-1304) and Oljeitu (Uljaytu, r. 1304-16), its aim was to set out the history and condition of the Mongol people, conquerors of the world (part one), followed by a description of the other peoples and nations of the world and their histories (part two). Given its unprecedented scope, Rashid, vizier to both rulers, mobilized a whole team of specialists, informants, and collaborators to assist him in his task. Making use of written and oral sources, the part on the Mongols is a key source on the emergence and organisation of the Mongol empire, while the second part constitutes the first attempt ever at writing a history of the world. The section published here describes the history of the Ismailis.