The Parliamentarians won the English Civil War in 1651, leading to the Protectorate led by Oliver Cromwell and the execution of King Charles I. Though the monarchy was restored in 1659 with Charles II's crowning, the rebellion established that the king could not rule without Parliament's support.
Charles I, unlike his father James I, was determined to rule as an absolute monarch. He did a number of things that upset the largely Protestant English parliament, including marrying a Catholic and refusing to call a parliamentary assembly for 11 years. When Charles finally called Parliament in order to raise money, the members refused to discuss taxes, instead bringing forth a decade's worth of grievances against him. Tensions rose for nearly two years during the Long Parliament. When Charles tried to have several of his parliamentary enemies arrested in 1642, open civil war broke out.