Before Gutenberg's printing press appeared in the 1450s, books in Europe were copied out by hand, a process so slow that a single volume could occupy a scribe for months. Printing did not immediately make books cheap, but it did make them far easier to reproduce in large numbers. Within fifty years, ideas that had once circulated among a handful of scholars were reaching readers across the continent, and rulers who had never worried about written material began trying to control what was printed.