The Anglo-Spanish War was a conflict between the English Protectorate under Oliver Cromwell, and Spain, between 1654 and 1660. It was caused by commercial rivalry. Each side attacked the other's commercial and colonial interests in various ways such as privateering and naval expeditions. In 1655, an English amphibious expedition invaded Spanish territory in the Caribbean. In 1657, England formed an alliance with France, merging the Anglo–Spanish war with the larger Franco-Spanish War resulting in major land actions that took place in the Spanish Netherlands.

The Commonwealth was the political structure during the period from 1649 to 1660 when England and Wales, later along with Ireland and Scotland, were governed as a republic after the end of the Second English Civil War and the trial and execution of Charles I. The republic's existence was declared through "An Act declaring England to be a Commonwealth", adopted by the Rump Parliament on 19 May 1649. Power in the early Commonwealth was vested primarily in the Parliament and a Council of State. During the period, fighting continued, particularly in Ireland and Scotland, between the parliamentary forces and those opposed to them, in the Cromwellian conquest of Ireland and the Anglo-Scottish war of 1650–1652.