In 1603 beloved Queen Elizabeth was succeeded by her Scottish cousin James Stuart, who ruled England as James I (r. 1603–1625). Like Louis XIV, James believed that a monarch had a divine right to his authority and was responsible only to God. James I and his son Charles I (r. 1625–1649) considered any legislative constraint on their power a threat to their divine-right prerogative. Consequently, at every meeting of Parliament between 1603 and 1640, bitter squabbles erupted between the Crown and the House of Commons.

Religious issues also embittered relations between the king and the House of Commons. In the early seventeenth century many English people felt dissatisfied with the Church of England. Calvinist Puritans wanted to take the Reformation further by “purifying” the Anglican Church of Roman Catholic elements, including crown-appointed bishops. James I responded to such ideas by declaring, “No bishop, no king.” His son and successor, Charles I, further antagonized subjects by marrying a French Catholic princess and supporting the high-handed policies of archbishop of Canterbury William Laud (1573–1645).

Charles avoided direct confrontation by refusing to call Parliament into session from 1629 to 1640, financing his government through extraordinary stopgap levies considered illegal by most English people. However, when Scottish Calvinists revolted against his religious policies, Charles was forced to summon Parliament to obtain funding for an army to put down the revolt. Angry with the king’s behavior and sympathetic with the Scots’ religious beliefs, the House of Commons passed the Triennial Act in 1641, which compelled the king to call Parliament every three years. The Commons also impeached Archbishop Laud and then threatened to abolish bishops. King Charles, fearful of a Scottish invasion, reluctantly accepted these measures. The next act in the conflict was precipitated by the outbreak of rebellion in Ireland. In 1641 the Catholic gentry of Ireland led an uprising in response to a feared invasion by British anti-Catholic forces.

Without an army, Charles I could neither come to terms with the Scots nor respond to the Irish rebellion. After a failed attempt to arrest parliamentary leaders, Charles left London and began to raise an army. In response, Parliament formed its own army, the New Model Army.

The English civil war (1642–1649) pitted the power of the king against that of Parliament. After three years of fighting, Parliament’s army defeated the king’s forces at the Battles of Naseby and Langport in the summer of 1645. Charles refused to concede defeat, and both sides waited for a decisive event. This arrived in the form of the army under the leadership of Oliver Cromwell, a member of the House of Commons and a devout Puritan. In 1647 Cromwell’s troops captured the king and dismissed members of the Parliament who opposed Cromwell’s actions. In 1649 the remaining representatives, known as the Rump Parliament, put Charles on trial for high treason. Charles was found guilty and beheaded on January 30, 1649.