Wikipedia

The Voynich manuscript is an illustrated codex hand-written in an unknown script referred to as 'Voynichese'. The vellum on which it is written has been carbon-dated to the early 15th century (1404–1438). Stylistic analysis indicates it may have been composed in Italy during the Italian Renaissance. The origins, authorship, and purpose of the manuscript are debated. Hypotheses suggest that it is a script for a natural language or constructed language; an unread code, cypher, or other form of cryptography; or a meaningless hoax.