Oliver Cromwell was arguably the most significant political figure in the early modern history of the British Isles. Yet he was also a military leader, with significant battlefield victories to his credit. Martyn Bennett here provides the first military biography of Cromwell in the context of the seventeenth century Military Revolution. After commanding a small troop in 1643 and, without prior military experience, Cromwell rose to lead the cavalry regiments of the Eastern Association Army and the New Model Army to final victory at Worcester in 1651 and sealed the victory of the Parliamentary forces in Ireland and Scotland, becoming Lord General in 1650. Martyn Bennett analyses Cromwell's military talents and generalship, in addition to his well-attested powerful and even brutal discipline and religious fervour. He examines the controversial Irish campaigns as well as modern accusations of genocide. In providing new perspectives on Cromwell's military career, Bennett adds to our understanding of England's only non-royal head of state.