Considered to be the first book printed with movable type was Gutenberg's Bible, printed around 1455. In which language was it written?

In the mid-15th century, Latin was the universal language of scholarship and, most importantly, of the Western Church. Johannes Gutenberg chose this language for his groundbreaking printing project because his text was the Vulgate, the Latin translation of the Bible completed by St. Jerome in the 4th century. For over a thousand years, the Vulgate had been the standard, authoritative biblical text for European Christendom, making it the only commercially and religiously viable choice for such an expensive and ambitious undertaking.

These Bibles were not intended for the average person, who typically could not read Latin or afford such a luxury item. The primary customers were wealthy churches, monasteries, and universities. In a nod to tradition, the printed pages were designed to mimic the appearance of hand-copied manuscripts. Gutenberg even left blank spaces in the text for professional scribes, known as illuminators, to later add the ornate, colorful capital letters and marginal decorations by hand, blending the new age of print with the artistry of the old.

While this first great printed book was inaccessible to the masses, the technology behind it would soon change everything. Gutenberg's movable-type press made it possible to produce books quickly and cheaply, paving the way for texts, including the Bible, to be printed in vernacular languages like German and English. This explosion of accessible information was a key catalyst for the Protestant Reformation, fundamentally reshaping European society.