Book of hours in the context of "The Very Rich Hours of the Duke of Berry"

Sowing is the process of planting seeds. An area that has had seeds planted in it will be described as a sowed or sown area.

In the practice of Christianity, canonical hours mark the divisions of the day in terms of fixed times of prayer at regular intervals. A book of hours, chiefly a breviary, normally contains a version of, or selection from, such prayers.

In the Roman Rite of the Catholic Church, canonical hours are also called officium, since it refers to the official prayer of the Church, which is known variously as the officium divinum ("divine service", "divine office", or "divine duty"), and the opus Dei ("work of God"). The current official version of the hours in the Roman Rite is called the Liturgy of the Hours (Latin: liturgia horarum) or divine office.

A psalter is a volume containing the Book of Psalms, often with other devotional material bound in as well, such as a liturgical calendar and litany of the Saints. Until the emergence of the book of hours in the Late Middle Ages, psalters were the books most widely owned by wealthy lay persons. They were commonly used for learning to read. Many psalters were richly illuminated, and they include some of the most spectacular surviving examples of medieval book art.

The English term (Old English psaltere, saltere) derives from Church Latin. The source term is Latin: psalterium, which is simply the name of the Book of Psalms (in secular Latin, it is the term for a stringed instrument, from Ancient Greek: ψαλτήριον psalterion).The Book of Psalms contains the bulk of the Divine Office of the Roman Catholic Church. The other books associated with it were the Lectionary, the Antiphonary, and Responsoriale, and the Hymnary.In Late Modern English, psalter has mostly ceased to refer to the Book of Psalms (as the text of a book of the Bible) and mostly refers to the dedicated physical volumes containing this text.

The Sforza Hours (British Library, London, Add. MS 34294), is a richly illuminated book of hours initiated by Bona Sforza, widow of Galeazzo Sforza, Duke of Milan, around 1490, who commissioned the illuminator Giovanni Pietro Birago [nl]. The book remained in an unfinished state for 30 years until Margaret of Austria, Regent of the Netherlands, commissioned its completion in 1517–20 from the artist Gerard Horenbout. The book therefore contains decoration of the highest quality by two artists. It provides a unique example of an early sixteenth-century Northern Renaissance illuminator's response to Milanese art of the late Quattrocento. The history of the Sforza Hours also includes one of the earliest recorded examples of art theft.

It has been in the British Library since 1893.

The Heures de Charles d'Angoulême is a book of hours commissioned in the late 15th century, probably around 1480, by Charles, Count of Angoulême, father of king Francis I of France. It is now in the Bibliothèque nationale de France in Paris, under the number Latin 1173.

The book contains full-page miniatures mostly painted by Robinet Testard, many of which have been adapted from, and inspired by, engravings, including sixteen prints by Israhel van Meckenem which have been glued onto the vellum and overpainted. The book is notable for both the quality of its art, and its various methods of incorporating prints, which testifies to the "complex history of interchanges between printed materials and manuscript illumination during the later fifteenth century".

The Petites Heures of Jean de France, Duc de Berry is an illuminated book of hours commissioned by John, Duke of Berry between 1375 and 1385–90. It is known for its ornate miniature leaves and border decorations.

Several artists were employed in the production. It was completed in two separate stages, each with a distinctive style. The earlier leaves were painted by artists influenced by Jean Pucelle, the later by artists working in the vanguard of the International Gothic period of Gothic art. Because of this, the Petites Heures exemplifies the "rupture in style" that occurred in French illumination in the final two decades of the fourteenth century.