The First English Civil War broke out in 1642, largely due to ongoing conflicts between James' son, Charles I, and Parliament. The defeat of the Royalist army by the New Model Army of Parliament at the Battle of Naseby in June 1645 effectively destroyed the king's forces. Charles surrendered to the Scottish army at Newark. He was eventually handed over to the English Parliament in early 1647. He escaped, and the Second English Civil War began, but the New Model Army quickly secured the country. The capture and trial of Charles led to the execution of Charles I in January 1649 at Whitehall Gate in London, making England a republic. This shocked the rest of Europe. The king argued to the end that only God could judge him.

The New Model Army, commanded by Oliver Cromwell, then scored decisive victories against Royalist armies in Ireland and Scotland. Cromwell was given the title Lord Protector in 1653, making him 'king in all but name' to his critics. After he died in 1658, his son Richard Cromwell succeeded him in the office but he was forced to abdicate within a year. For a while it seemed as if a new civil war would begin as the New Model Army split into factions. Troops stationed in Scotland under the command of George Monck eventually marched on London to restore order.

According to Derek Hirst, outside of politics and religion, the 1640s and 1650s saw a revived economy characterized by growth in manufacturing, the elaboration of financial and credit instruments, and the commercialization of communication. The gentry found time for leisure activities, such as horse racing and bowling. In the high culture important innovations included the development of a mass market for music, increased scientific research, and an expansion of publishing. All the trends were discussed in depth at the newly established coffee houses.