The oldest known version of the Gutenberg Bible, the first major book produced on a printing press, was completed.

The Gutenberg Bible, also known as the 42-line Bible, the Mazarin Bible or the B42, was the earliest major book printed in Europe using mass-produced metal movable type. It marked the start of the "Gutenberg Revolution" and the age of printed books in the West. The book is valued and revered for its high aesthetic and artistic qualities and its historical significance.

A printing press is a mechanical device for applying pressure to an inked surface resting upon a print medium, thereby transferring the ink. It marked a dramatic improvement on earlier printing methods in which the cloth, paper, or other medium was brushed or rubbed repeatedly to achieve the transfer of ink and accelerated the process. Typically used for texts, the invention and global spread of the printing press was one of the most influential events in the second millennium.