The Italian humanist Polydore Vergil (1470-1555) was born in Urbino but spent most of his life in early Tudor England. His most popular work, "On Discovery" ("De inventoribus rerum," 1499), was the first comprehensive account of discoveries and inventions written since antiquity. Thirty Latin editions of this work were published in Polydore's lifetime, and by the eighteenth century more than a hundred editions had appeared in eight languages, including Russian. "On Discovery" became a key reference for anyone who wanted to know about "firsts" in theology, philosophy, science, technology, literature, language, law, material culture, and other fields. Polydore took his information from dozens of Greek, Roman, biblical, and Patristic authorities. His main point was to show that many Greek and Roman claims for discovery were false and that ancient Jews or other Asian peoples had priority. This is the first English translation of a critical edition based on the Latin texts published in Polydore Vergil's lifetime.