The Ilkhanate or Il-khanate was a Mongol khanate founded in the southwestern territories of the Mongol Empire. It was ruled by the Il-Khans or Ilkhanids, and known to the Mongols as Hülegü Ulus. The Ilkhanid realm was officially known as the Land of Iran (Irānzamin) or simply Iran. It was established after Hülegü, the son of Tolui and grandson of Genghis Khan, inherited the West Asian and Central Asian part of the Mongol Empire after his brother Möngke Khan died in 1259.