Introduction to the Cai Clan Ancestral Hall: The surname Cai is a common surname in Fujian Province. According to statistics in 2007, it ranks 11th in the province and 44th in the country. The ancestor of the Cai surname can be traced back to Cai Shudu in the early Western Zhou Dynasty, who was the fifth son of King Wen of Zhou and the younger brother of King Wu of Zhou. After King Wu conquered the Shang Dynasty, his uncle was granted the title of Cai (now Shangcai County, Henan Province) and was known as Uncle Cai in history. After King Wu died and King Cheng succeeded to the throne, Cai Shu and others launched a rebellion. After being punished by Zhou Ping, they were exiled. After that, King Zhou Cheng still granted Cai Shu's son Hu to Cai.