Johann Gutenberg was a German inventor who transformed how books were made around 1440 by developing a printing press that used movable type. Before Gutenberg, many books in Europe had to be copied by hand, one at a time, making books extremely rare and expensive. A single Bible might take a monk an entire year to copy.

Gutenberg's key innovation was creating individual metal letters that could be arranged into words, inked, pressed onto paper, then rearranged to print the next page. Think of it like using rubber stamps for each letter, except far more precise and durable. His press could produce hundreds of identical pages in the time it once took to copy a single page by hand.

His most famous work, the Gutenberg Bible, appeared around 1455 and is considered one of the most beautiful books ever printed. Within fifty years of his invention, millions of books spread across Europe, making knowledge accessible to far more people than ever before. Ideas could now travel faster than ever.

Gutenberg's invention helped spark the Renaissance, the Scientific Revolution, and the Reformation. It's hard to imagine our modern world without his contribution: before Gutenberg, most people never owned a single book. After his invention, the written word became a force that could reach people across many parts of society.