James Ussher counted biblical generations like a detective tracking suspects. The Archbishop of Armagh became famous for precisely dating creation to October 23, 4004 BC, a wildly specific moment that would make scientists and theologians debate for centuries. Born on January 4, 1581, in Dublin, Ussher was ordained at 20 and appointed to the chair of theological controversies at Trinity College Dublin before most scholars had finished their studies. His magnum opus, the Annales Veteris Testamenti, published in 1650, traced every genealogy and chronology in the Bible against known historical records, cross-referencing Babylonian, Greek, and Roman sources to build a continuous timeline from creation to 70 AD. The calculation was not the work of a naive literalist. Ussher was one of the most learned men in Europe, fluent in multiple ancient languages and deeply familiar with secular historical scholarship. He cataloged medieval Irish manuscripts at a time when most were letting them crumble, preserving texts that would otherwise have been lost entirely. His personal library of over 10,000 books and manuscripts was one of the largest in the British Isles and was bequeathed to Trinity College Dublin after his death in 1656. The date of creation he calculated was printed in the margins of the King James Bible for over two centuries, giving it an authority far beyond what Ussher himself claimed. He never said it was divine revelation. He said it was the best calculation the evidence allowed.