First. Index. Ever.
Saint Augustine of Hippo — bishop, confessor, and Doctor of the Roman Church was a thoughtful and persuasive writer of the Fifth Century. Among many other topics, he wrote on homiletics, the study of Christian rhetoric and oratory. In 1467 his writing on The Art of Preaching was published by Peter Schöffer and Joahn Fust, colleagues of Johannes Gutenberg. It contained the first known alphabetical index.