Jin, originally known as Tang (唐), was a major state during the middle part of the Zhou dynasty, based near the centre of what was then China, on the lands attributed to the legendary Xia dynasty: the southern part of modern Shanxi. Although it grew in power during the Spring and Autumn period, its aristocratic structure saw it break apart when the duke lost power to his nobles. In 403 BC, the Zhou court recognized Jin's three successor states: Han, Zhao, and Wei. The Partition of Jin marks the end of the Spring and Autumn period and the beginning of the Warring States period.

Ancient Chinese states were dynastic polities of China within and without the Zhou cultural sphere prior to Qin's wars of unification. They ranged in size from large estates, to city-states to much vaster territories with multiple population centers. Many of these submitted to royal authority, but many did not—even those that shared the same culture and ancestral temple surname as the ruling house. Prior to the Zhou conquest of Shang, the first of these ancient states were already extant as units of the preceding Shang dynasty, Predynastic Zhou, or polities of other cultural groups. Once the Zhou had established themselves, they made grants of land and relative local autonomy to kinfolk in return for military support and tributes, under a system known as fengjian.