The English Interregnum was the period of parliamentary and military rule in the land occupied by modern-day England and Wales after the English Civil War. It began with the execution of Charles I in 1649 and ended when Charles II became king in 1660. Oliver Cromwell had died in 1658.
This era in English history can be divided into four periods:
Oliver Cromwell was a Puritan, and during the Interregnum, he imposed a very strict form of Christianity upon the country. Although a main cause of the English Civil War had been oppression under Charles I, England during the Interregnum became oppressive in its own way. Cromwell granted religious freedom that had otherwise been unknown in England, but other forms of expression were suddenly limited. (For instance, theatre, which had thrived under the Stuart kings and Elizabeth I, was banned.) Cromwell also made sure that his own personal vision of Christianity was enforced upon the masses. Many of Cromwell's actions were called "harsh, unwise, and tyrannical" by some commentators.
After Cromwell's death, his son Richard Cromwell quit his position as Lord Protector with little hesitation. He resigned, or "abdicated", after a demand by the Rump Parliament. That began a short period of restoration of the Commonwealth of England.
The English Restoration soon happened, when Charles II came to power.