Cavalier was the name used by Parliamentarians for a Royalist supporter of King Charles I during the English Civil War (1642–1651). Prince Rupert, commander of much of Charles I's cavalry, is often considered an archetypical Cavalier. Early usage Cavalier derives from the Spanish word caballeros, itself originating in the Vulgar Latin word caballarius, meaning horseman. Shakespeare used the word cavaleros to describe an overbearing swashbuckler or swaggering gallant in Henry IV, Part 2, i… (More on Cavalier)