Jī (姬) was the ancestral name of the Zhou dynasty which ruled China between the 11th and 3rd centuries BC. Thirty-nine members of the family ruled China during this period while many others ruled as local lords, lords who eventually gained great autonomy during the Spring and Autumn and Warring States periods. Ji is a relatively uncommon surname in modern China, largely because its bearers often adopted the names of their states as new surnames.
The character is composed of the radicals 女 (Old Chinese: nra, "woman") and 𦣞 (OC: ɢ(r)ə, "chin"). It is most likely a phono-semantic compound, with nra common in the earliest Zhou-era family names and ɢ(r)ə marking a rhyme of 姬 (OC: K(r)ə).
The legendary and historical record shows the Zhou Ji clan closely entwined with the Jiang (姜), who seem to have provided many of the Ji lords' high-ranking spouses. A popular theory in recent Chinese scholarship has suggested that they represented two important clans – the Ji originally centered on the Fen River in Shanxi and the Jiang around the Wen River in Shaanxi – whose union produced the Zhou state ruled by Old Duke Danfu, although the theory remains problematic.
In the family hymns recorded in the Classic of Poetry, the Ji (姬) family is traced from the miraculous birth of the Xia dynasty culture hero and court official Houji caused by his mother's stepping into a footprint left by the supreme god Shangdi. The Records of the Grand Historian instead make Houji the son of the Emperor Ku, descendant of Yellow Emperor.