The Book of Hours was popular in middle ages. The decorations are mostly restricted to capital letters. Every example of a book of hours is unique on its own right but they all share some common properties. They all include prayers with appropriate decorations.
Book of Hours are very decorative and illuminated. Jewels are sometimes used on the covers. Not all of them were illustrated but today they are known best for their decorations. These books are very important for the study of late medieval prayers but most of all because of the decorations and illuminations, late medieval art.
Book of Hours were very popular during Middle Ages. It was the main prayer book of monarchy, lords, ladies etc. This popularity though was not everywhere. It was mostly resttriced to parts of Europe: Netherlands, England, France.