The clan forces, whose predecessor was gens forces in the tribal era, was a special military in the preQin period. In the legend era, the war between the Huang Emperor, Yan Emperor and Chiyou was mainly reliant on the gens forces, even if in the Xia Dynasty, the gens forces still existed, which changed into clan forces after the establishment of the Shang Dynasty. Yin Ruins inscriptions of the late Shang Dynasty have multiple entries involving clan forces, including royal clan, prince clans and other different surname noble clans, who fought against the opposing state alone or with national army. There are lots of combat records about clan forces in the inscription on the bronze of the West Zhou Dynasty from King Kang to King Xuan. Yu Ding and Duoyou Ding show clearly that these clan forces were allegiance to the patriarch who served as a Duke in the central dynasty, not the King of Zhou. Before the middle of the Spring and Autumn Period, the clan forces of the high ministers were limited by one hundred chariots, but entering the later stage, their forces became stronger unprecedentedly. It was not until the Warring states period that the clan forces declined gradually.

the clan forces; the gens; patriarchal clan community; military system in the Shang and Zhou Dynasties