Arguably the closest that Britain has ever come to military rule was at certain times during the period from 1647 to 1660. English forces conquered Ireland and Scotland in 1649–50 and 1650–1 respectively, and the two kingdoms were then forcibly ‘settled’ and incorporated into an English commonwealth. In England, meanwhile, the army repeatedly intervened to purge or disperse parliaments: in 1647, 1648, 1653, 1654, and 1659 (twice). For about fifteen months, in 1655–7, England and Wales were governed by major-generals who exercised sweeping powers to enforce order, preserve security, and enforce a ‘reformation of manners’. All these developments raise profound questions about the nature of Cromwellian government in general, and the relationship between politics and military rule in particular. Austin Woolrych argued, some years ago, that the Cromwellian Protectorate was not a military dictatorship in any meaningful sense. He suggested that the regime possessed neither the will, nor the means, to impose military rule, that it generally respected the rule of law, and that the military presence in local government even during the time of the major-generals was limited. Yet the nature of the interaction between the military and the political – in shaping government, in influencing policies, and in forming the careers of Oliver Cromwell and other leading figures – remains complex and merits much fuller exploration. The four books under review address these and related themes from a range of different viewpoints.