'The Book of Jasher' is said to derive from a manuscript that was discovered by the Romans after the fall of Jerusalem in 70 AD. It appeared in Europe as a printed version at Venice in 1613. From internal evidence it seems to date from around the time of the Babylonian and Jerusalem Talmudic literature - it may even be contemporary with the 'Book of Enoch'. The book is enormously valuable as an adjunct to Biblical studies. It contains historical information that can help to fill in historical gaps in the Biblical narrative, such as the reason for Cain and Tubal Cain's deaths, and the true identity of Melchizedek. There are also many problematical comments, while others directly contradict orthodox Jewish rites, such as Rachel's use of necromancy and the practice of astrology by Benjamin. 'The Book of Jasher' is a document that both enlightens and disturbs in equal measure - a book that cannot and should not be ignored.