The wars left England, Scotland, and Ireland among the few countries in Europe without a monarch. In the wake of victory, many of the ideals became sidelined. The republican government of the Commonwealth of England ruled England (and later all of Scotland and Ireland) from 1649 to 1653 and from 1659 to 1660. Between the two periods, and due to in-fighting among various factions in Parliament, Oliver Cromwell ruled over the Protectorate as Lord Protector (effectively a military dictator) until his death in 1658.

On Oliver Cromwell's death, his son Richard became Lord Protector, but the Army had little confidence in him. After seven months the Army removed Richard. In May 1659 it re-installed the Rump. Military force shortly afterward dissolved this as well. After the second dissolution of the Rump, in October 1659, the prospect of a total descent into anarchy loomed, as the Army's pretense of unity dissolved into factions.

Into this atmosphere General George Monck, Governor of Scotland under the Cromwells, marched south with his army from Scotland. On 4 April 1660, in the Declaration of Breda, Charles II made known the conditions of his acceptance of the Crown of England. Monck organised the Convention Parliament, which met for the first time on 25 April 1660.

On 8 May 1660, it declared that Charles II had reigned as the lawful monarch since the execution of Charles I in January 1649. Charles returned from exile on 23 May 1660. On 29 May 1660, the populace in London acclaimed him as king. His coronation took place at Westminster Abbey on 23 April 1661. These events became known as the Restoration.

Although the monarchy was restored, it was still with the consent of Parliament. So the civil wars effectively set England and Scotland on course towards a parliamentary monarchy form of government. The outcome of this system was that the future Kingdom of Great Britain, formed in 1707 under the Acts of Union, managed to forestall the kind of revolution typical of European republican movements which generally resulted in total abolition of their monarchies. Thus the United Kingdom was spared the wave of revolutions that occurred in Europe in the 1840s. Specifically, future monarchs became wary of pushing Parliament too hard, and Parliament effectively chose the line of royal succession in 1688 with the Glorious Revolution.