According to the Columbia Encyclopedia, Cathay (kăthā') was the name for North China and used by medieval Europeans. It is derived from the Khitan (or Khitai), a Manchurian people who conquered S Manchuria and N China and founded the Liao dynasty (937-1125).

S China was referred to as Mangi. Long after the end of the Liao, the Russians and some central Asian people continued to and still use Kitai as the name of China. The description of Cathay by Marco Polo (c.1254-c.1324) in his journal helped popularize the name in medieval Europe.