The family descended from Marquis Xian of Jin 晉獻侯 (r. 823-812) and therefore bore the family name of Ji 姬. Qi Xi was the first family member elevated to the rank of grand master (dafu 大夫) and was given the fief of Qi 祁 (modern Qixian 祁縣, Shanxi). The name of the land was later used as a kinsname (shi 氏). The family had many branches like the kinsgroup Qicheng 祁成氏 or Qiye 祈夜氏 (also written Qiyi 祈射).
The most important members of the house of Qi were:
Qi Xi 祁奚 (祈奚)
Qi Wu 祁午 (祈午)
Qi Ying 祁盈 (祈盈)