In ancient China, the patriarchal clan system (Chinese: 宗法; pinyin: zōngfǎ; lit. 'clan law') of the Zhou cultural sphere was a primary means of group relations and power stratification prior to the Western Zhou and through the first half of the Eastern Zhou dynasty. This method of social organisation underlay and prefigured the political workings of the Zhou state. The patriarchal system was based on blood relations, with firstborn succession at its core, and played a role in maintaining the Western Zhou political hierarchy and stabilizing social order.[1][2] Together with the ritual and music system it is seen as having been the foundation of Zhou society.[3][better source needed]