Emperor Zhaozong of Tang
It is not known when or where Wang Kai was born. It is known that he served as an emissary of Emperor Zhaozong of Tang during the "Tianfu" era (901-904) to Xichuan Circuit (西川, headquartered in modern Chengdu, Sichuan) late in Tang Dynasty, and thereafter remained in Xichuan, which was then ruled by Wang Jian.