Book of Hours, Besançon, France, c1430–40, Rare Books collection

Books of Hours were private devotional works widely used during the medieval period, detailing a program of prayers to be recited at set intervals throughout the day. They frequently used texts, such as the Mass for the Dead, shown here. Wealthy people usually commissioned these books from secular commercial (as opposed to monastic) workshops, and they were often richly illustrated according to the owner's preferences.