At the beginning of 220, Cao Cao died and was succeeded by his son Cao Pi. On 11 December, Emperor Xian abdicated and Cao Pi ascended the imperial throne by proclaiming the heavenly mandate as the Emperor of Wei. On 15 May 221, Liu Bei responded by proclaiming himself as the Emperor of Han. His state would become generally known as Shu Han. Sun Quan continued to recognize his "de jure" suzerainty to Wei and was enfeoffed as the King of Wu.