September 18, 2017 Leaf 8 8. A Book of Hours calendar leaf (ca. 1400) The book of hours is a devotional book extremely popular in the Middle Ages. Most contain a similar collection of texts, prayers and psalms, often with appropriate decorations, for Christian devotion. Illumination or decoration is minimal in many examples, often restricted to decorated capital letters at the start of psalms and other prayers, but books made for wealthy patrons were extremely lavish, with full-page miniatures. A typical book of hours contained a calendar of Church feasts. Leaf 9 Leaf 4