After the Gospel Lessons comes the heart of every Book of Hours, the series of prayers called the Hours of the Virgin (hence the name Book of Hours or, in Latin, Horae). There are eight separate Hours: Matins, Lauds, Prime, Terce, Sext, None, Vespers, and Compline. Each Hour consists mostly of Psalms, plus varying combinations of hymns, prayers, and readings (lessons), to which innumerable short ejaculations (antiphons, versicles, and responses) are generously sprinkled. Ideally these eight Hours were prayed throughout the course of the day: Matins and Lauds were said together at night or upon rising, Prime (the first hour of the day according to ancient Roman, and thus medieval Church, time) around 6 A.M., Terce (the third hour) at 9 A.M., Sext (the sixth hour) around noon, None (the ninth hour) at 3 P.M., Vespers (evensong) in early evening, and Compline before retiring.
Descriptions of Books of Hours frequently include the “use” (use of Rome, use of Paris, etc.). Calendars help determine where Books of Hours are used, but technically speaking the use of the Hours of the Virgin is determined by changes in the antiphons and capitula (responsive prayers and little chapters) found at the end of Prime and None. It is astonishing how many different uses have been identified and some from towns quite near one another (Caen and Rouen, for example), suggesting that liturgical use was highly local. The reasons behind these variations are still insufficiently understood. With a few skills, anyone can identify the “use” of the Hours of the Virgin, thanks to online resources that have become available.
The Hours of the Virgin can be traced back to at least the ninth century; tradition holds that they were developed by Benedict of Aniane (c. 750-821). At first, the Hours of the Virgin began to be added to the Divine Office, the daily round of prayers the medieval Church required of its ordained: priests, monks, and nuns. By the mid-eleventh century, they were an established practice. The Hours would be chanted, in choir, from Antiphonaries. By the late twelfth century, the Hours were also found in Psalters, the prayer books containing the Psalms used, in this era of emerging literacy, by both the ordained and the laity. By the mid-thirteenth century, these hybrid Psalter-Hours lost their Psalter sections and, retaining their Calendars and Offices of the Dead, became the core of the prayer book known as the Book of Hours.
Part of the attraction of the Hours of the Virgin for the laity is their simplicity. Although some Psalms for Matins change depending on the day of the week, and some Horae include some minor textual variations for Advent and Christmastide, the same basic Hours of the Virgin were prayed day in, day out. This constancy was clearly a comfort. Repeated on a daily basis from childhood to old age, the Hours of the Virgin became a familiar, steadfast friend. Variety could be achieved by adding, mixing, or substituting the Hours of the Cross and the Hours of the Holy Spirit, or, indeed, any of the multiple prayers contained within a typical Book of Hours.
By the mid-sixteenth century, we reach the end of the Hours of the Virgin's popularity with the laity: the manuscripts cease to be commissioned and the printed editions peter out. There is no edition of the Hours of the Virgin in print. The text that constituted the core of the medieval bestseller can be devilishly hard to find today (Latin-English editions, printed as late as the 1960s, can sometimes be had from secondhand bookshops). There is a Hypertext available on the Internet.