In 1448, after the initial printing trials in Strassburg, Gutenberg returned to Mainz. There in 1452 at the latest he started with the "Work of the Books", the printing of the Vulgate Bible of St. Hieronymus, the decisive text for every theological work and religious instruction throughout the entire Middle Ages.

For this work he needed a financial backer. Johannes Fust lent Gutenberg the sum of 800 guilders in 1449 and then, in 1452, another 800 guilders. Enea Silvio Piccolomini, who later became Pope Pius II, reported in 1455 that he had seen several printed quires of the Bible in October 1454 at a congress of German princes and prelates in Frankfurt. This indicates that the printing had been completed by that time.

On the last pages of the two volumes of a paper copy at the Bibliothèque Nationale in Paris there is a comment to the effect that this copy was rubricated, illuminated and bound on the 15th respectively the 24th of August 1456. Thus, at this point in time, the Bible must have been complete.