In the English Civil War, the supporters of King Charles I were referred to pejoratively as the “Cavaliers,” a word which carried charged meanings in 17th century England. The Cavaliers generally referred to themselves as “Royalists,” referencing their support for the King of England in his struggle against the Parliamentarians. The term “Cavalier” certainly caught on, and many references to Cavaliers and Roundheads can be heard in discussions of the English Civil War.
The English Civil War was actually a series of wars, not just a single conflict, in the mid-1600s in which the King struggled for power against the Parliament. The Parliamentarians disapproved of the actions of the Monarchy, and they wanted to empower themselves to make better decisions for England. There were three conflicts in all; the Second English Civil War actually ended with the regicide of King Charles I, and the third was sparked by rebellion in Ireland and Scotland before it was ultimately put to a stop by the Parliamentarians.
The Parliamentarians referred to their opponents as Cavaliers in the hopes of belittling their position. The term is derived from the French chevalier, for knight, and it was meant to imply a certain sense of self righteousness and fashion consciousness. The Cavaliers were perceived as reckless supporters of the King, and the term was supposed to suggest carelessness, hard drinking, and impious living. The term was also a reference to a line in Shakespeare, in which cavaliers are implied to be swashbuckling, arrogant individuals.
Ultimately, the Cavaliers started to adopt the term for themselves, trying to turn it into an empowering and honorable title rather than a demeaning one. As contemporary writings suggest, several Cavaliers spoke in eloquent defense of the Royalist position and their lifestyles. They also retaliated with a pejorative of their own: Roundhead, for the simply dressed and plainly styled Puritan Parliamentarians. The term “Roundhead” is said to be a reference to the tightly cropped hairstyles of many Parliamentarians, which were markedly different from the flowing and carefully styled locks of the Cavaliers.
Ultimately, the Cavaliers lost the English Civil War, but they did not chafe under Parliamentary rule for long. A mere 12 years after Oliver Cromwell and his fellow Roundheads founded the Republican Commonwealth, Charles II was brought back from exile and the monarchy was restored. The sense of cavalier as reckless or haughty continues to live on in modern English.