Books of hours

Books of hours were usually written in Latin (they were largely known by the name horae until "book of hours" was relatively recently applied to them), although there are many entirely or partially written in vernacular European languages, especially Dutch. The closely related primer is occasionally considered synonymous with books of hours – a medieval horae was referred to as a primer in Middle English – but their contents and purposes could deviate significantly from the simple recitation of the canonical hours. Tens of thousands of books of hours have survived to the present day, in libraries and private collections throughout the world.