It has long been a truism that the Bible is the most-published book in the history of Western culture. But for almost 250 years, from about 1275 to 1525, Books of Hours (illuminated prayer books whose heart is a series of prayers devoted to the Virgin Mary) were the medieval best sellers.
During this period the Book of Hours was the book most frequently commissioned by both the aristocracy and the middle classes. On the pages of Books of Hours the best artists created the most beautiful pictures, and the prayers on these pages offered the reader an intimate conversation with one of the mostimportant people in medieval Christian religious life, the Virgin Mary.
The Book of Hours evolved from the clerical breviary. Medieval clergy were required by the Roman Catholic Church to recite daily the Divine Office, a complicated series of prayers that changed every day. Priests, monks and nuns fulfilled this obligation by singing their prayers from large choir books called antiphonaries or, most often, by reciting from prayer books, breviaries, which contained the prayers, hymns, psalms and readings of the Divine Office.