When Tekuder assumed the throne in 1282, he turned the Ilkhan empire into a sultanate. Tekudar zealously propagated his new faith and sternly required his ranking offices to do the same. However his nephew Arghun, the governor of Khorasan, was a Buddhist; and asked Kublai Khan, emperor of the Yuan Dynasty for help. Although, Kublai was angry with the situation, Arghun had to overthrow the ilkhan himself.
Tekuder sent friendly letter to Mamluk sultan and wished a peace. His conversion to Islam and good ties with Mamluks were not seen well by Mongol nobles.
When Arghun received no reply, he declared war against Tekuder. Tekuder asked for help from the Mamluk Sultan but the Mamluks did not fully co-operate with Tekuder. Having only a small army, Tekuder was defeated by Arghun's large army, and he was eventually executed on August 10, 1284.