In this thesis, I analyze the Akītu festival for the purpose of understanding the socio-political landscape of the Neo- and Late-Babylonian periods in Babylon (626 BCE - 100 BCE). The history of the Akītu festival, known as the Mesopotamian New Year’s festival, spans several millennia, but was especially known in its 1st millennium form in Babylon. This analysis focuses on the relationship between kings, gods, and high priests of Babylon and their actions in an historical and social space with relation to this festival. The interaction between cult and state in this shared space is used to compare how each empire utilized the festival and gods in order to exert and subvert power over the other within both an historic context and a wider socio-political history. I show that the Akītu festival was a constantly developing festival that was as dependent on the ruling king as it was a defining factor of kingship in Babylon.