[from the Latin decorus, ‘seemly’]
Originally a literary term, it is first used in relation to the visual arts in the Renaissance in the writings of Leonardo da Vinci. According to Leonardo's theory of Decorum, the gestures which a figure makes must not only demonstrate feelings, but must be appropriate to age, rank, and position. So must also be dress, the setting in which the subject moves, and all the other details of the composition. Such thinking greatly influenced academic art, in particular history painting, from the Renaissance through to the 19th century.