Book of Hours were prayer books designed for the laity, but modeled on the Divine Office, a cycle of daily devotions, prayers and readings, performed by members of religious orders and the clergy. Its central text is the Hours of the Virgin. There are eight hours (times for prayer ): Matins, Lauds. Prime, Terce, Sext, None, Vespers and Compline. During the Middle Ages, the leaves making up a Book of Hours were written by hand on expensive parchment and beautifully illuminated with jewel-like pigments and gold leaf. These illuminated manuscripts combined the collaborative efforts of an array of highly skilled craftspeople; requiring the joint labors of the parchmenter, professional scribes to write the text in Gothic script, artists to illuminate the pages with decorations, and masterful binders to complete the process.

This vellum leaf is from a Book of Hours written in Normandy, for the use of Coutances. It was once owned by Seigneur Richard du Mesnildot, Provost Royal of Coutances in 1489. The leaf is embellished with seven initials and three line fillers [one is a flower] in red, blue, white and gold leaf. The largest initial has a bunch of flowers in the margin. Text is from Psalm 66.
Translation of the Latin text, beginning with the large illuminated initial: God have mercy upon us, and bless us: illuminate his countenance upon us, and have mercy upon us. That we may know thy way in earth: in all nations thy salvation. Let peoples O God confess to thee: let all peoples confess to thee. Let nations be glad and rejoice, because thou judgest peoples in equity: and the nations in the earth thou dost direct. Let peoples o God confess to thee, let all peoples confess to thee: the earth [ hath yielded her fruit. God our God bless us, God bless us: and let all the ends of the earth fear him.

References:

Condition: A

Some foxing in margins.