"Roundhead" was the nickname given to the supporters of Parliament during the English Civil War. Also known as Parliamentarians, they fought against King Charles I who claimed absolute power and the divine right of kings.

Most roundheads appear to have sought a constitutional monarchy, in place of the absolutist monarchy sought by Charles I, but at the end of the Second Civil War in 1649, republican leaders such as Oliver Cromwell were in a strong position to abolish the monarchy completely and establish the republican Commonwealth. The roundhead commander-in-chief of the first Civil War, Lord Fairfax, remained a supporter of constitutional monarchy, as did many other roundhead leaders such as Edward Montagu.

Roundheads tended to be Puritan or Presbyterian, but also included many smaller groups such as the Independents. Roundhead political factions included Diggers, Levellers, and Fifth Monarchy Men.

The Roundheads' enemies, the Royalist supporters of King Charles I of England, were nicknamed Cavaliers.

Origins and background

"Roundheads" appeared to have been first used as a term of derision towards the end of 1641, when the debates in Parliament in the Bishops Exclusion Bill were causing riots at Westminster. Some, but by no means all, of the Puritans wore their hair closely cropped round the head, and there was an obvious contrast between them and the men of courtly fashion with their long ringlets. One authority said of the crowd which gathered there, "They had the hair of their heads very few of them longer than their ears, whereupon it came to pass that those who usually with their cries attended at Westminster were by a nickname called Roundheads." According to John Rushworth (Historical Collections), the word was first used on 27 December, 1641 by a disbanded officer named David Hide, who during a riot is reported to have drawn his sword and said he would "cut the throat of those round-headed dogs that bawled against bishops".

However, Richard Baxter ascribes the origin of the term to a remark made by Queen Henrietta Maria at the trial of the Earl of Strafford earlier that year; referring to John Pym, she asked who the roundheaded man was.

The principal advisor to Charles II, the Earl of Clarendon (History of the Rebellion, volume IV. page 121) remarked on the matter, "and from those contestations the two terms of 'Roundhead' and 'Cavalier' grew to be received in discourse, ... they who were looked upon as servants to the king being then called 'Cavaliers,' and the other of the rabble contemned and despised under the name of 'Roundheads' ".

Ironically, after Anglican Archbishop Laud made a statute in 1636 instructing all clergy to wear short hair, many Puritans rebelled to show their contempt for his authority, and began to grow their hair even longer (as can be seen on their portraits), though they continued to be known as Roundheads. The longer hair was more common among the "Independent" and "high ranking" Puritans (which included Cromwell), especially toward the end of the Protectorate, while the "Presbyterian" (i.e. non-Independent) faction, and the military rank-and-file, continued to abhor long hair. By the end of this period, some Independent Puritans were again derisively using the term Roundhead to refer to the Presbyterian Puritans.