Abaqa Khan
His historical work "Nizam al-Tawarikh" (The Ordering of Histories) was written in Persian, his native language. It seems to be part of an effort to encourage Abaqa Khan, the Buddhist ruler of Iraq to legitimize Ilkhanate rule in Iraq by conversion to Islam. This work played a key-role in the formation of the ethno-national history of Iran, being the first book devoted to its national history.