Watch: How experts stumbled upon a priceless document in a university library

A manuscript - erstwhile considered an unofficial transcript of Magna Carta - is present believed to beryllium a genuine mentation and ''one of the world's astir invaluable documents'', according to UK academics.

Harvard Law School paid $27.50 (then astir £7) for it successful 1946 and for years it has remained tucked distant successful its library, its existent individuality unknown.

But 2 medieval past professors person concluded it is an extraordinarily uncommon and mislaid archetypal Magna Carta from 1300 - and could beryllium worthy millions.

BBC Newsbeat's Eleanor Doyle explains.

Video by Tom Joyner, Anna Lamche, Ian Casey and Tom Richardson.