Hermes Trismegistus, meaning Hermes the Thrice-greatest, was the Greek name for the Egyptian god Thoth. To him was ascribed the invention of writing and the authorship of the Hermetic Writings, books of occult wisdom which date from the 1st to the 4th centuries AD. They were of great importance in medieval European thought, since they were held to date from before the writings of Moses, and thus provide access to the body of primordial knowledge that had since been lost.