Prayers said at specific times of the day in various Christian denominations.

Early 15th-century French book of hours (MS13, Society of Antiquaries of London), open to illustration of 'Adoration of the Magi'. Given to the Society in 1769 by the Rev Charles Lyttleton, Bishop of Carlisle and President of the Society (1765-8).

The Hours are a Christian devotional book popular in the Middle Ages. It is the most common type of surviving medieval illuminated manuscript. Like any manuscript, each manuscript of a book of hours is unique in one way or another, but most contain similar a collection of texts, prayers, and psalms, often with appropriate decorations, for Christian devotion. Illumination or decoration is minimal in many examples, often limited to decorated large letters at the beginning of psalms and other prayers, but books made for wealthy patrons could be extremely lavish, with full-page miniatures. These illustrations would combine picturesque scenes of rural life with sacred images. Books of hours were usually written in Latin (the Latin name for them is horae), although many are written entirely or partially in European languages, especially Dutch. The English term primer is now usually reserved for those books that are written in English. Tens of thousands of horae books have survived to this day, in libraries and private collections around the world.

Typical Prayer The Office of the Hours is an abbreviated form of the breviary, which included the Office of God recited in monasteries. It was developed for lay people who wished to incorporate elements of monasticism into their devotional lives. The recitation of the Hours typically focused on the reading of many psalms and other prayers. Typical examples include the Calendar of Ecclesiastical Feasts, excerpts from the Four Gospels, the Mass readings for major feasts, the Little Office of the Blessed Virgin Mary, the fifteen Psalms of Degrees, and the seven Penitential Psalms, Litany Saints, Office of the Dead and Hour of the Cross.

Most 15th-century books of hours have these basic contents. Marian prayers Obsecro te ("I beseech thee") and O Intemerata ("O undefiled one") were often added, as well as devotions for use at Mass and meditations on the Passion, among other optional texts.

Even this level of decoration is richer than most books, though less than the large amounts of illumination in luxury books that are most commonly found in reproduction.

The prayer of the Hour has its ultimate origin in the Psalter, which monks and nuns were required to recite. By the 12th century it had developed into a breviary, with weekly cycles of psalms, prayers, hymns, antiphons and readings that changed with the liturgical season. Eventually a selection of texts was produced in much shorter volumes and came to be known as the Book of Hours. In the second half of the 13th century, the Prayer of the Hours became popular as a personal prayer book for men and women who led secular lives. It consisted of a selection of prayers, psalms, hymns and lessons based on the liturgy of the clergy. Each book was unique in its content, although all contained the Hours of the Virgin Mary, devotions celebrated during the eight canonical hours of the day, which provided justification for the name "Prayer Hour".

Many books of hours were created for women. There is some evidence that they were sometimes given as a wedding gift by a husband to his wife. They were often passed down through the family, as recorded in wills.

Although the most heavily illuminated books of hours were enormously expensive, a small book with little or no illumination was much more widely and increasingly available in the fifteenth century. The earliest surviving English example was apparently written for a layman living in or near Oxford around 1240. It is smaller than a modern paperback, but heavily illuminated with large initials, but no full-page miniatures. By the 15th century there are also examples of servants having their own Books of Hours. In a court case from 1500, a poor woman is accused of stealing a domestic servant's prayer book.

Very rarely these books contained prayers specifically composed for their owners, but more often the texts are tailored to their taste or gender, including the inclusion of their names in the Prayers. Some of them contain pictures depicting their owners, and some contain coats of arms. These, along with a selection of saints commemorated in the calendar and election, are the main clues to the identity of the first owner. Eamon Duffy explains how these books reflected the person who commissioned them. He states that 'the personal nature of these books was often signalled by the inclusion of prayers specially composed or adapted for their owners'. He further claims that "as many as half of the surviving manuscripts of the Books of Hours have annotations, marginalia, or additions of some kind. Such additions may merely signify the inclusion of some regional or personal patron in a standard calendar, but often include devotional material added by the owner. Owners could write in dates that were important to them, notes on months when things happened that they wanted to remember, and even images found in these books would be personalized to the owners - such as local saints and local celebrations. By at least the 15th century, hour books were being produced in Dutch and Parisian workshops to be kept or distributed, rather than waiting for individual orders. Sometimes spaces were left in them to add personalized elements, such as local holidays or heraldry.

The style and layout of traditional hour books became increasingly standardized around the mid-13th century. The new style can be seen in books produced by Oxford illuminator William de Brailes, who ran a commercial workshop (he was in small orders). His books included various aspects of the church breviary and other liturgical aspects for use by the laity. "It included a perpetual calendar, the Gospels, prayers to the Virgin Mary, the Stations of the Cross, prayers to the Holy Spirit, penitential psalms, litanies, prayers for the dead and selections for the saints. The purpose of the book was to help its pious patroness in ordering her daily spiritual life according to the eight canonical hours, Matins to Compline, observed by all pious members of the Church. The text, complete with rubrics, gilding, miniatures and beautiful illuminations, sought to stimulate meditation on the mysteries of faith, the sacrifice made by the Christ for man and over the horrors of hell, and especially to emphasize devotion to the Virgin Mary, which was at its zenith in the thirteenth century." This arrangement was maintained over the years as many aristocrats commissioned their own books.

Decorations

Full-page miniature of May, from Simon Benning's calendar cycle, early 16th century.
Because many books of hours are richly illuminated, they provide an important record of life in the 15th and 16th centuries, as well as an iconography of medieval Christianity. Some of them were also decorated with jewels, portraits and heraldic coats of arms. Some were bound in girdles for easy carrying, although few of these or other medieval bindings have survived. Luxury books, such as the Talbot Hours by John Talbot, 1st Earl of Shrewsbury, may contain a portrait of the owner, or in this case his wife, kneeling in adoration of the Virgin and Child, as a form of donor portrait. In expensive books, miniature cycles showed the Life of the Virgin or the Passion in eight scenes adorning the eight hours of the Virgin, and Labyrinths of the months and signs of the zodiac adorning the calendar. The secular scenes of the calendar cycles include many of the best-known images from the books of hours and played an important role in the early history of landscape painting.

Used books of hours were often modified for new owners, even among rabbits. After Richard III was defeated, Henry VII gave the book of hours to Richard's mother, who modified it to include his name. Heraldry was usually erased or overpainted by new owners. Many have handwritten annotations, personal additions and notes in the margins, but some new owners also commissioned new craftsmen to include more illustrations or text. Sir Thomas Lewkenor of Trotton employed an illustrator who added details to what are now known as the Lewkenor Hours. The leaves of some surviving books contain notes on household bookkeeping or records of births and deaths, along the lines of later family bibles. Some owners also collected autographs of notable visitors to their home. Books of hours were often the only book in the house and were commonly used to teach reading by children, sometimes they had an alphabet page to help them with that.

By the late 15th century, printers were producing books of hours with woodcut illustrations, and the Prayer of the Hour was one of the major works decorated in the related woodcut technique.

Luxury Prayer Hour

The rich illusionistic borders of this late 1700s Flemish book of hours are typical of luxury books of the period, which were now often decorated on every page. The butterfly wing cutting into the text area is an example of the play with visual conventions typical of the period.

(Among the plants are Veronica, Vinca, Viola tricolor, Bellis perennis and Chelidonium majus. The butterfly is Aglais urticae. The Latin text is dedicated to Saint Christopher).
By the fourteenth century, the Prayer of the Hours had overtaken the psalter as the most common vehicle for lavish illumination. This reflected in part the growing dominance of illuminations, both commissioned and executed by laymen rather than monastic clerics. From the late fourteenth century, many bibliophilic royal figures began to collect luxurious illuminated manuscripts for their decorations, a fashion that spread throughout Europe from the courts of Valois in France and Burgundy, as well as Prague under Charles IV, Holy Roman Emperor, and later Wenceslas. A generation later, Prince Philip the Good of Burgundy was the most important collector of manuscripts, and several of his circle also collected. It was during this period that the Flemish cities overtook Paris as the leading force in the Enlightenment, a position they retained until the final decline of the enlightened manuscript in the early 16th century.

The most famous of all collectors, French Prince John, Duke of Berry (1340-1416) owned several books of hours, some of which survive, including the most famous of them, the Très Riches Heures du Duc de Berry. These were begun around 1410 by the Limbourg brothers, though not completed by them, and the decoration continued for several decades by other artists and owners. The same was true of the Turin-Milan Hours, which also passed through Berry's ownership.

By the mid-fifteenth century a much wider group of nobles and wealthy businessmen were able to order highly decorated, often small, books of hours. With the advent of printing the market shrank sharply, and by 1500 the highest quality books were again produced only for royalty or very large collectors. One of the last large illuminated books of hours was the Farnese Hours completed for the Roman Cardinal Alessandro Farnese in 1546 by Giulio Clovio, who was also the last large manuscript illuminator.

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