Jerome

Jerome translated the Bible into Latin and gave the Western church a single text to argue about for the next thousand years. The Vulgate is his — and 'translating' undersells it. He learned Hebrew at a time when no Christian did, went to Bethlehem, and worked from the original texts rather than the Septuagint. He was prickly, vicious in argument, and impossible to live with. But every time the West read scripture from 400 to 1500, they were reading Jerome.