In 1450, all western Europe's books were handcopied and amounted to no more than a single modern library. By 1500 they were printed and numbered in their millions. Printing made possible the development of modern science and literature, and the political shift from statelets to nations. It brought about the biggest changes in human culture since the invention of the alphabet itself. The man responsible was Johann Gutenberg, born in 1400 in Mainz, Germany. John Man explains how this technical genius whose research into printing was funded by wealthy sponsors, struggled against a background of plague, religious upheaval and legal battles to bring his remarkable invention to light.