This ground-breaking volume fills a major historiographical gap by providing the first detailed book-length study of the period of the Cromwellian Protectorate from December 1653 to May 1659. The study is very broad in its scope, covering topics as diverse as the British and Irish dimensions of the Protectorate Parliaments, the political and social nature of factions, problems of management, the legal and judicial aspects of Parliament's functions, foreign policy and the nature of the parliamentary franchise and elections in this period. In its wide-ranging analysis of Parliaments and politics throughout the Protectorate the book also examines both Lord Protectors, all three Protectorate Parliaments and the reasons why Oliver and Richard Cromwell were never able to achieve a stable working relationship with any Parliament. Its chronological coverage extends to the demise of the Protectorate in May 1659. This comprehensive account will appeal to historians of early modern British political history.