This essay revisits the issue of ‘indemnity’ for behaviour undertaken on behalf of the parliamentarian cause during the civil wars, not least by members of the army. This is an issue that has generated historiographical debate, in terms of whether or not contemporary debates over the issue serve to reveal parliamentarian ‘tyranny’, and in terms of how to understand the ‘rise of the New Model Army’ as a political force in the late 1640s. This essay seeks to draw connections between two different ways of analysing ‘indemnity’, as a practical political issue and as something that raised theoretical and constitutional questions, and builds upon scholarship regarding the need to set soldiers’ concerns within the context of questions about legality, justice, necessity and tyranny. The aim is to stress the importance of placing ‘indemnity’ at the heart of the process by which contemporaries thought about the business of political settlement with the king, of the possibility of bringing him to justice, and of the struggle for the post-war constitution, and to demonstrate that soldiers’ demands regarding indemnity are key to understanding the ideological radicalisation of the army.