At the intervention of Hulagu's Nestorian Christian wife, Dokuz Khatun, the city's Christian inhabitants were spared.[38][39] Hulagu offered the royal palace to the Nestorian Catholicos Mar Makikha, and he also ordered that a cathedral should be built for him.[40] Ultimately, the seventh ruler of the Ilkhanate, Mahmud Ghazan, converted from Tengrism to Islam, and thus began the gradual decline of Tengrism and Buddhism in the region and its replacement by the renaissance of Islam.