Why were books locked in chests during middle ages?

Books were locked in chests during the Middle Ages to protect them from theft, damage, and unauthorized access. Books were valuable and labor-intensive to produce, often being handwritten by scribes on parchment or vellum. Locking them in chests helped safeguard these precious and rare items from being stolen or mishandled. Additionally, during this time period, literacy was limited to a select few, so restricting access to books also served to control who could read and interpret their contents.