His first printed book, and definitely the most important, is known as the Gutenberg Bible, which was the Latin version of the Bible used at the time. This is the oldest book still in existence ("extant") in the West. He was printing copies of the Bible by 1455.
The invention of the printing press is considered one of the greatest inventions of all time, and it had an enormous impact on Europe. The Reformation in the following century relied on the printing press to circulate translations of the Bible in German to the public. Before Johann Gutenberg and the press, no common person could own their own copy. Gutenberg's printing press, while invaluable to society, was a financial disaster. He fell into such debt that his presses were confiscated as collateral.
- Azimov, Isaac. Isaac Asimov's Book of Facts. New York: Random House, 1979.