A courser is a swift and strong horse, frequently used during the Middle Ages as a warhorse.
Coursers are commonly believed to be named for their running gait,[1] (from Old French cours, 'to run'[2]).
However, the word possibly derived from the Italian corsiero, meaning 'battle horse'.
[3] The courser was more common than the destrier,[4] and used for battle as they were light, fast and strong.
[1] They were valuable horses, but less expensive than the highly prized destrier.