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) over the territory 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)