Chivalry, or the chivalric code, is an informal, varying code of conduct developed between 1170 and 1220, but never decided on or summarized in a single document. It was associated with the medieval Christian institution of knighthood; knights' and gentlewomen's behaviours were governed[when?] by chivalrous social codes The ideals of chivalry were popularized in medieval literature, especially the Matter of Britain and Matter of France, the former informed by Geoffrey of Monmouth's Historia Regum Britanniae, written in the 1130s, which popularized the legend of King Arthur.All of these were taken as historically accurate until the beginnings of modern scholarship in the 19th century.

The code of chivalry that developed in medieval Europe had its roots in earlier centuries. It arose in the Holy Roman Empire from the idealisation of the cavalryman—involving military bravery, individual training, and service to others—especially in Francia, among horse soldiers in Charlemagne's cavalry. The term "chivalry" derives from the Old French term chevalerie, which can be translated as "horse soldiery".[Note 1] Originally, the term referred only to horse-mounted men, from the French word for horse, cheval, but later it became associated with knightly ideals.

Over time, its meaning in Europe has been refined to emphasise more general social and moral virtues. The code of chivalry, as it stood by the Late Middle Ages, was a moral system which combined a warrior ethos, knightly piety, and courtly manners, all combining to establish a notion of honour and nobility