Michelino's contemporaries regarded him as the "supreme painter" and the "most excellent of all the painters in the world." This small prayer book, which contains most of his surviving work, is his masterpiece. Here St. Luke the evangelist is putting the finishing touches on a small panel of the Virgin and Child. This is one of the earliest Western depictions of the subject, which became increasingly popular later in the century because St. Luke was the patron saint of painters and painters' guilds.