Scholars generally date completion of the Gutenberg Bible—also called the 42-line Bible—to around February 1455, based on a letter from that time describing the finished work being shown at the Frankfurt fair. The roughly 180 copies produced revolutionized the spread of knowledge across Europe, ending the monopoly monks and scribes held over book production.
Gutenberg's genius wasn't the idea of printing—block printing existed in Asia for centuries—but a system: reusable metal type cast in molds, an oil-based ink that would adhere to metal rather than the water-based inks used for wood blocks, and a modified wine press to apply even pressure. Each letter was cast individually and could be rearranged infinitely.
Producing the roughly 1,300-page Bible took years and consumed enormous resources; Gutenberg borrowed heavily from investor Johann Fust, who eventually sued him and seized the print shop and much of the equipment before the project even finished, a bitter irony given the scale of what had been achieved.
Of the estimated 180 copies printed—some on paper, some on vellum requiring the skins of entire herds of calves—only 48 survive today, scattered across libraries and museums, some complete, many fragmentary. A single leaf can now fetch six figures at auction. The technology spread across Europe within decades, and within fifty years, printing presses operated in over 250 cities, fundamentally reshaping the Reformation, science, and literacy itself.