James' son, Charles I and the English Parliament fought each other in the English Civil War (Scotland and Ireland were involved as well, but the story is complicated!). Oliver Cromwell became leader of the Parliamentary Army (the "Roundheads") and defeated the Royalist Army (the "Cavaliers"). King Charles was beheaded in 1649 and Oliver Cromwell became dictator ("Lord Protector"). When Cromwell died, his son Richard was not strong enough to rule, and Charles II, the son of Charles I, was invited to come to England and be king in 1660. 