Shire Book: Eric Monk documents in this fully illustrated book the story of the key. The oldest keys known to exist date from around 4,000 BC in Ancient Egypt. These simple wooden cylinders that were part of a mechanism to secure doors. By the time of the Roman Empire, metal keys were in common usage and had begun to adopt the recognizable pattern of keys today. These days, old keys are more than just security mechanisms, they are highly collectable artifacts. Shire Library Softcover.