JAMES i. (1603-25) united the crowns of England and Scotland, though not their parliaments or administrations.

He rapidly grew unpopular through his pro-Spanish and anti-Presbyterian inclinations, and through his attempts to tax London's trade without the consent of Parliament. His foreign policy was elaborately absurd, and at his death he left England floundering in a backwater of the Thirty Years' War. Charles I. (1625-49) was soon driven by Parliamentary opposition to retire from the war, as the only condition on which he could do without Parliamentary grants. For eleven years (1629-40) he raised small illegal taxes, or taxes that were legal but obsolete and vexatious, and encouraged Archbishop Laud to enforce High Church ritual, but did not give his confidence to the very able man who could perhaps have made him a despot, Strafford. The country gentlemen afterwards called this the " Eleven Years' Tyranny," an exaggeration; but they undoubtedly felt a sense of grievance over Laud's religious policy and trifles like the King's Ship Money tax. Laud used various weapons of Church discipline harshly against Puritan clergy and against Puritan laymen who criticised his views of doctrine, ritual, and government, e.g., the celebrated pamphleteers, Prynne, Burton, and Bastwick. This " Eleven Years' Tyranny," however, was a golden age in contrast to the insane bloodshed of the Continent and the turmoil that soon followed in England.

Charles and Laud provoked a Presbyterian rebellion in Scotland and had to ask Parliament's help. Parliament, led by Pym and Hampden, executed Strafford, made Charles agree to several reforms which he would not have carried out, and then split over religion. A bare majority of the Commons wished to introduce Presbyterianism. In 1642 the King, most of the peers, and the strong minority of Commons who loved the English Church more than they disliked arbitrary taxation, raised forces to crush London and the rebellious majority in the House.

In the war that followed, the King's supporters were drawn largely from the north and west of England and from Ireland, Parliament's from London, the south-east, the Midlands, and the seaports. The Parliamentary forces had much greater resources in money, and enforced closer organisation and stricter discipline than the Cavaliers. Moreover, they were assisted by the Scots between 1644 and 1646. They were handicapped by weak leadership, but the Puritan element in their forces displayed a combination of fanaticism and coolness that proved irresistible. Cromwell, the leader of the Puritan element, was mainly responsible for the victories of Marston Moor and Naseby. When it appeared impossible to nail Charles down to pledges, Cromwell took the lead in overriding the moderate Parliamentarians and bringing Charles to the block.

After crushing the Irish and then the Scots, who had originally supported Parliament, Cromwell used the magnificent Puritan navy and army in wars against Protestant Holland and Catholic Spain in a manner that Charles and Stratford would have envied. The naval and military expenses of the republic made the government insolvent, and necessitated far heavier taxation than Charles had ever levied. The Puritans tried to suppress drunkenness and various forms of amusement, and these endeavours added to their political unpopularity; the extreme Puritans had never been more than a small section of the upper and middle class, and they held power now only because they controlled fifty thousand excellent troops.

After Cromwell's death, General Monk brought Charles II. back in 1660. Puritanism was defeated; the upper-class Puritans joined the Church of England, while the poorer Puritans kept their separatist or Nonconformist congregations alive, but were subject for some years to penalties and exclusion from public life. The political and financial side of the Parliament's cause was won. There was to be no taxation without consent of Parliament, which was to meet regularly. Its temper was ardently Royalist and Anglican. Catholicism was not tolerated any more than Puritanism.