The First English Civil War took place in England and Wales from 1642 to 1646, and forms part of the 1639 to 1653 Wars of the Three Kingdoms. An estimated 15% to 20% of adult males in England and Wales served in the military at some point between 1639 and 1653, while around 4% of the total population died from war-related causes. These figures illustrate the widespread impact of the conflict on society, and the bitterness it engendered as a result.

The Wars of the Three Kingdoms, sometimes known as the British Civil Wars, were a series of intertwined conflicts fought between 1639 and 1653 in the kingdoms of England, Scotland and Ireland, then separate entities united in a personal union under Charles I. They include the 1639 to 1640 Bishops' Wars, the First and Second English Civil Wars, the Irish Confederate Wars, the Cromwellian conquest of Ireland and the Anglo-Scottish War of 1650–1652. They resulted in victory for the Parliamentarian army, the execution of Charles I, the abolition of monarchy, and founding of the Commonwealth of England, a unitary state which controlled the British Isles until the Stuart Restoration in 1660.