Under the impact of the sovereign debt crisis, SYRIZA emerged as a major political actor in Greek politics. Its evolution from a minor oppositional force to a governing party expressed and simultaneously shaped the dynamics that transformed the Greek party system from 2010 onwards. Moreover, its clash with the creditors in 2015 over the terms of the third Greek bail-out marked a turning point in the trajectory of the Eurozone crisis. As a result, the party figured prominently in many studies dealing with post-crisis Greek and European politics. Unfortunately, a sizeable part of this literature is characterised by significant misconceptions with regards to the party’s strategy and discourse. To remedy this, we undertook a thorough examination of its ideologico-political trajectory from the time of its inception as an electoral front in 2004 up until its removal from power in 2019. In terms of data, our research is based on an in-depth analysis of party documents, written testimonies and interviews with key party insiders. This allows for a sound understanding of the party’s positioning, its internal conflicts and the dynamics that shaped its policy over critical issues, such as the bail-outs, the coalition with the Independent Greeks and the Prespes Agreement.