A gentleman (Old French: gentilz hom, gentle + man) is any man of good and courteous conduct. Originally, gentleman was the lowest rank of the landed gentry of England, ranking below an esquire and above a yeoman; by definition, the rank of gentleman comprised the younger sons of the younger sons of peers, and the younger sons of a baronet, a knight, and an esquire, in perpetual succession. As such, the connotation of the term gentleman captures the common denominator of gentility (and often a coat of arms); a right shared by the peerage and the gentry, the constituent classes of the British nobility.

Therefore, the English social category of gentleman corresponds to the French gentilhomme (nobleman), which in Great Britain meant a member of the peerage of England. In that context, the historian Maurice Keen said that the social category of gentleman is "the nearest, contemporary English equivalent of the noblesse of France." In the 14th century, the term gentlemen comprised the hereditary ruling class, which is whom the rebels of the Peasants' Revolt (1381) meant when they repeated:

When Adam delved and Eve span,
Who was then the gentleman?

In the 17th century, in Titles of Honour (1614), the jurist John Selden said that the title gentleman likewise speaks of "our English use of it" as convertible with nobilis (nobility by rank or personal quality) and describes the forms of a man's elevation to the nobility in European monarchies. In the 19th century, James Henry Lawrence explained and discussed the concepts, particulars, and functions of social rank in a monarchy, in the book On the Nobility of the British Gentry, or the Political Ranks and Dignities of the British Empire, Compared with those on the Continent (1827).