Defining a British State explores the formation of the British state and national identity from 1603 through 1820 by examining the definitions of sovereignty and allegiance presented in treason trials. The king's person remained central to national identity and the state until republican challenges forced prosecutors in treason trials to innovate and redefine sovereign authority. Although jurors resisted the change, by the 1790s parliament and prosecutors accepted that treason law protected all Britons and 'the general safety of the state'.