This research projects aims to understand the roots of the "dual sex" political institutions of eastern Nigeria, whereby men and women are represented by separate hierarchies headed by a king (Obi) and an unrelated queen (Omu). At least since Engels, the rise of the state has been associated with the creation of gender hierarchies. Yet in eastern Nigeria it instead led women to innovate a parallel set of political institutions to counterbalance the increased power of men. This happened in a context where women could draw on many sources of empowerment. First, the dominance of female deities in Igbo cosmology, who determined exit from and entry to the spiritual realm: this realm played an important role in politics since ancestors were an active part of the community. Second, the ritual separation of gender roles in agriculture and trade, which appear in Igbo myths of origins: this stopped women being secluded or marginalized socially or economically. Finally, the ability of women to act collectively through such institutions as the Umuada, the association of eldest daughters who had to assemble for any burial. We argue that the unique combination of these three elements gave women the ability to resist the potentially gendered tyranny of state formation and create an institution unique in world history.