Long Parliament, the name commonly given to the English Parliament that sat during the Great Rebellion. The Long Parliament met from 1640 to 1653, and from 1659 to 1660. During this period King Charles I was put to death and England was declared a commonwealth. The earlier Short Parliament, which met for three weeks in 1640, had been dominated by the king. The Long Parliament, on the other hand, was the real ruling power of England until the rise of Oliver Cromwell in the 1650's. Never again was the monarchy to dominate Parliament.

The Long Parliament first convened in 1640, and under the leadership of John Pym and John Hampden it passed a series of bills designed to weaken the power of the king. After Charles tried to arrest Pym, Hampden, and three other members of the House of Commons, civil war broke out. Royalist members of Parliament resigned or were expelled. The remaining members were largely Puritans who believed in Presbyterianism. In 1643, Parliament entered into a treaty with the Scots, binding England to establish Presbyterianism in return for Scottish aid. A minority in Parliament, the Independent Puritans, however, opposed the agreement.

With the help of the Scots, Parliament defeated the Royalists, and King Charles was captured in 1646. Meanwhile, the Independents, led by Oliver Cromwell, had become the most powerful force in the Parliamentary armies. Civil war broke out again, this time over the issue of establishing Presbyterianism. In this conflict, the Independents opposed the combined forces of the Presbyterian faction in Parliament, the Scots, and the king.

The Independents won in 1648, and the Presbyterians were then barred from Parliament. Only about 60 members remained; they came to be known as the “Rump” Parliament. In 1649 it abolished the monarchy and the House of Lords and established the court that had the king put to death.

In 1653 Cromwell forced Parliament to disband and had the army name him lord protector of England, making him virtual dictator. After his death the remaining members of the Long Parliament reconvened. They were persuaded to make way for a newly elected Parliament in 1660 and the monarchy was restored.