Hulagu Khan was a Mongol ruler who conquered much of Southwest Asia. Son of Tolui and the Kerait princess Sorghaghtani Beki; he was a grandson of Genghis Khan; and the brother of Arik Boke; Mongke Khan and Kublai Khan. Hulagu's army greatly expanded the southwestern portion of the Mongol Empire; founding the Ilkhanate of Persia; a precursor to the eventual Safavid dynasty; and then the modern state of Iran. Under Hulagu's leadership; the Mongols destroyed the greatest center of Islamic power; Baghdad; and also weakened Damascus; causing a shift of Islamic influence to the Mamluks in Cairo. It was also in Hulagu's reign that historians switched from writing in Arabic to writing in Persian.