Despite his collection of women, however, Cao Rui was without any son who survived infancy. He adopted two sons to be his own -- Cao Fang and Cao Xun, whom he created princes in 235. (It is usually accepted that they were sons of his cousins, although the exact parentage is not clear.) In 237, Cao Rui took the unprecedented (and unrepeated in Chinese history) action of setting his own temple name of Liezu and ordering that his temple, in the future, never to be torn down. (Based on Confucian regulations, except for the founder of the dynasty, rulers' temples would be destroyed after six generations.) He carried out these actions apparently in apprehension that he would be given an unflattering temple name (or none at all) and that his temple would eventually be destroyed, due to his lack of biological issue and unclear origin.