During the 1620's and 30's, King Charles I came into serious conflict with Parliament. Charles demanded new taxes and levies that Parliament refused to grant, so the king dissolved Parliament and sought to run the kingdom by himself. Hamstrung by his inability to raise new taxes, Charles summoned a new Parliament in 1640. He tried to dissolve that one, believing they had gone too far when it issued the Grand Remonstrance and moved to arrest 5 of its leading members, including Pym. But they had been tipped off beforehand and fled to London. English Civil War began.

The Cavaliers, loyal to the king and Roundheads, supporting Parliament, came to heads in the Battle of Edgehill in Oct 1642. It was an inconclusive battle. 1643 Pym died. January 1644, the Scots invaded England. Prince Rupert went to battle at Marston Moor, but was defeated by Oliver Cromwell, who was the primary leader of the Roundheads. 14 June 1645 Battle of Naseby, Prince Rupert of the Rhine, was again brought to defeat by the Parliamentary forces.

1646 Charles surrendered to the Scots who turned him over to Parliament in Feb 1647. Nov 1647 Charles escaped and began negotiations with Parliament and the Scots. Cromwell went north and defeated the Scots at the Battle of Dunbar in 1648. Charles who had joined the Scotish army, was recaptured. 59 Judges signed the death warrant for the King and he was trailed for treason and beheaded on January, 30 1649.