Passage: In late 1299, the Mongol Ilkhan Mahmud Ghazan, son of Arghun, took his army and crossed the Euphrates river to again invade Syria. They continued south until they were slightly north of Homs, and successfully took Aleppo. There, Ghazan was joined by forces from his vassal state of Cilician Armenia. The Mamluk relief force sent from Damascus met the Mongol army northeast of Homs, at the Battle of Wadi al-Khazandar  in December 1299. The Mongols had some 60,000 troops, with about 40,000 Georgian and Armenian auxiliaries, and routed the Egyptian Mamluks with their much smaller force of 20,000-30,000 troops. The Mamluks retreated, and were harassed by Maronite and Druze bowmen who wanted independence from the Mamluks. One group of Mongols also split off from Ghazan's army, and pursued the retreating Mamluk troops as far as Gaza, pushing them back to Egypt. Question: Who was Ilkhan Mahmud Ghazan's father?
father = 'Arghun'

print(father)