English Civil War
The English Civil War of 1642-1651 saw the country divided between the supporters of Parliament under Oliver Cromwell and those loyal to King Charles I. Over the years there were several major battles and sieges, ending with Parliamentary victory at the Battle of Worcester on 3rd September 1651. Parliamentary forces are still referred to as the 'Roundheads', while the Royalists to this day are known as 'Cavaliers'.
From 1649 to 1659 the monarchy was abolished and replaced by the Commonwealth of England (1649-1653; 1659-1660) and a Protectorate (1653-1659), a military regime headed by Cromwell and later his son Richard.
First Civil War
By the autumn of 1643, two-thirds of England and Wales were under the King's control; in spite of minor successes achieved at Grantham, Gainsborough, and Winceby, where Cromwell served his apprenticeship in the art of war, the prognosis was poor for Parliament's army. In desperation the Parliamentary leaders came to terms with the Scottish leaders, and a Scottish army entered England in 1644.
Oliver Cromwell, now a lieutenant general, fought alongside the Scots and a northern army under Lord Fairfax and his son, Sir Thomas, at the Battle of Marston Moor in Yorkshire on 2nd July 1644, where the King's army, led by Prince Rupert, was outnumbered and defeated. Next year, fighting without the Scots, Cromwell again took part in the defeat of Prince Rupert at the Battle of Naseby on 14th June 1645. King Charles allowed his stronghold of Oxford to capitulate in June 1646, and himself fled to seek the mercy of the Scottish army.
Second Civil War and execution of Charles I
While Sir Thomas Fairfax dealt with Royalist risings in south-east England, Cromwell first suppressed a rebellion in Wales, and then marched north to meet the Scots. He won a series of decisive victories over the larger Scottish army, in Lancashire (August 1648), marking his first major success as an independent commander. While the Presbyterians in Parliament still hoped to reach agreement with Charles I, Cromwell's son-in-law Henry Ireton led a movement to punish the king and overthrow the old monarchy. In December 1648, the southern army "purged" the Commons of its Presbyterian members and demanded the trial of the king.
During the autumn, Cromwell had followed his retreating enemy into Scotland, and restored order in Edinburgh, but he had lingered in the north until General Fairfax recalled him to London. When he got back to the capital he approved of the purge, and took charge of the arrangements to bring Charles I to his trial under guard. Fairfax having washed his hands of all political matters, Cromwell accepted the responsibilities of leadership. He realized that the trial of the King would result in the latter's death, as a result of all the blood shed in the civil wars. Once he made up his mind, Cromwell acted ruthlessly, and it was largely by his personal efforts that the trial by what was in effect a revolutionary tribunal was pressed through, and the King was condemned to death.
On 30th January 1649, King Charles I was beheaded on a block in view of a silent crowd gathered in front of the Banquet Hall of Whitehall Palace; the king's noble death proved a rallying point for his supporters. After the execution of Charles I, England became a republic until 1660.