Cai

Chinese 蔡: from the name of the former state of Cai, in present-day Henan province. When the Zhou dynasty displaced the Shang dynasty in 1122 BC, the defeated Shang were allowed to rule in the area of their old capital of Yin, under the stewardship of Zhou appointees. However, these Zhou appointees, among them Cai Shu, the 14th son of Wen Wang and younger brother of the new king, joined forces with the Shang in revolt. After the rebellion was suppressed, Cai Shu was banished, but his son was granted the state of Cai along with the title Earl of Cai. His descendants later adopted the place name Cai as their surname. Other spellings of this name, due to dialect differences and variation in Romanization, include Tsai, Choi, Choy, and Tsoi.