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.