 In spring 538, in order to create an alliance with Rouran, Yuwen first had Emperor Wen bestow the title of Princess Huazheng to Yuan Yi (元翌), the daughter of a member of the imperial clan, to marry her to Yujiulü Tahan (郁久閭塔寒), the brother of Rouran's Chiliantoubingdoufa Khan Yujiulü Anagui.But Yuwen, believing that to be insufficient, requested Emperor Wen divorce his wife Empress Yifu and marry Yujiulü Anagui's daughter.Emperor Wen was forced to agree, and he deposed Empress Yifu, ordering her to become a Buddhist nun, and married Yujiulü Anagui's daughter as empress.