The Gutenberg Bible (also known as the 42-line Bible, the Mazarin Bible or the B42) was among the earliest major books printed using mass-produced movable metal type in Europe. It marked the start of the "Gutenberg Revolution" and the age of printed books in the West. Widely praised for its high aesthetic and artistic qualities,[1] the book has iconic status. It is an edition of the Vulgate printed in the 1450s in Latin by Johannes Gutenberg in Mainz, in present-day Germany. Forty-nine copies (or substantial portions of copies) have survived. They are thought to be among the world's most valuable books, although no complete copy has been sold since 1978.[2][3] In March 1455, the future Pope Pius II wrote that he had seen pages from the Gutenberg Bible displayed in Frankfurt to promote the edition. It is not known how many copies were printed; the 1455 letter cites sources for both 158 and 180 copies. The 36-line Bible, said to be the second printed Bible, is also referred to sometimes as a Gutenberg Bible, but may be the work of another printer.

The most reliable information about the Bible's date comes from a letter. In March 1455, the future Pope Pius II wrote that he had seen pages from the Gutenberg Bible, being displayed to promote the edition, in Frankfurt.[11] It is not known how many copies were printed, with the 1455 letter citing sources for both 158 and 180 copies. Scholars today think that examination of surviving copies suggests that somewhere between 160 and 185 copies were printed, with about three-quarters on paper and the others on vellum.[12][13] However, some books say that about 180 copies were printed and it took about three years to produce them.