The English Revolution (1640-1660), which involved the period known as the English Civil Wars (1642-1651), initially involved fighting between forces loyal to the Stuart King, Charles I, and forces loyal to Parliament. Charles was unpopular because he disbanded parliament from 1629-1640, a time known as the Eleven Year Tyranny. The civil wars were in part a reaction to uprisings in Ireland and Scotland, and they involved fighting between Cavaliers, who were loyal to the king, and Roundheads (named because of their flat hairstyles), who were loyal to Parliament and sought to curb the king's power. The Roundheads included Presbyterians and Puritans, while Cavaliers were generally Anglican, meaning they were from the Church of England.
The Revolution was fairly radical at points, as Charles I was tried and executed in 1649. At that point, until 1653, England was ruled as a Republic rather than a constitutional monarchy. England was then ruled as a Protectorate under Oliver Cromwell until 1659. The Revolution can be deemed a failure because Charles II, Charles I's son, assumed the monarchy in 1660 in what is known as the Restoration. While he permitted some religious tolerance, Charles II was still recognized as having the divine right of kings. The monarch did not cede much power to Parliament until the Bill of Rights in 1689, which resulted from the Glorious Revolution. This document stated that Parliament was required to meet regularly and citizens could enjoy freedom of speech and free elections. Parliament did not receive the power they sought in the English Revolution until the later Glorious Revolution of 1688.