This book examines the historical development and the legal and political scope of prerogative powers and Crown immunities as they affect the exercise of rights by citizens and non-citizens. It traces the changing relationship between individual and state, from subjecthood and allegiance to the Crown in a secretive state, to a participating legal and political citizenship in an open society and a widening British and European context. It addresses issues of key importance in the current constitutional debate about political and legal accountability, citizenship and human rights, and contributes to the debate about the future of the British monarchy and its remaining constitutional functions.