Man-at-arms (also called armsman or coistrel) was a term used from the High Medieval to Renaissance periods to describe a soldier, almost always a professional warrior in the sense of being well-trained in the use of arms, who served as a fully armoured heavy cavalryman. It could refer to knights or noblemen, and to members of their retinues or to mercenaries in companies under captains. Such men could serve for pay or through a feudal obligation. The terms knight and man-at-arms are often used interchangeably, but while all knights certainly were men-at-arms, not all men-at-arms were knights.

In the Early Medieval period, any well-equipped horseman could be described as a "knight", or miles in Latin. In the course of the 12th century knighthood became a social rank with a distinction being made between milites gregarii (non-noble cavalrymen) and milites nobiles (true knights). As a fully armoured cavalryman could be of a lesser social status than a knight, an alternative term describing this type of soldier came into use which was, in French, homme d'armes or gen d'armes, and in English man-at-arms. The term man-at-arms thus primarily denoted a military function, rather than a social rank. This evolution differed in detail and timeline across Europe but by 1300, there was a clear distinction between the military function of the man-at-arms and the social rank of knighthood.

Captain America is a fictional character, a superhero who appears in comic books published by Marvel Comics. The character first appeared in Captain America Comics #1 (cover-dated March 1941), from Marvel Comics' 1940s predecessor, Timely Comics, and was created by Joe Simon and Jack Kirby. As of 2007, an estimated 210 million copies of "Captain America" comic books had been sold in 75 countries. For nearly all of the character's publication history, Captain America was the alter ego of Steve Rogers, a frail young man who was enhanced to the peak of human perfection by an experimental serum in order to aid the United States war effort. Captain America wears a costume that bears an American flag motif, and is armed with an indestructible shield that can be thrown as a weapon.

An intentionally patriotic creation who was often depicted fighting the Axis powers of World War II, Captain America was Timely Comics' most popular character during the wartime period. After the war ended, the character's popularity waned and he disappeared by the 1950s aside from an ill-fated revival in 1953. Captain America was reintroduced during the Silver Age of comics when he was revived from suspended animation by the superhero team the Avengers in The Avengers #4 (March 1964). Since then, Captain America has often led the team, as well as starring in his own series.