This chapter traces the development of the crisis and civil war in Syria through the identification of four distinct but overlapping phases, which structure and set the context for the analysis in the book’s second half. The focus here is on domestic developments within Syria, rather than Anglosphere foreign policy. First, the origins of the crisis are mapped out, beginning with the regional Arab Uprisings in the spring of 2011. During this phase of the conflict, the crisis in Syria developed as a battle for human rights and democratic reform. Second, the chapter traces the war’s next phase, which was dominated by concerns about – and the use of – chemical weapons, following Obama’s 2012 pronouncement of a red line and the subsequent attack in Ghouta in 2013. Third, the chapter charts the rise of Islamic State in 2014. In this period, Syria became the epicentre of a new War on Terror. Fourth, from late summer 2015, the chapter traces the emergence of Syria as an explicit site of Great Power proxy warfare, following the intervention of Russia on behalf of Assad.