April 11, 146 AD — Septimius Severus, Roman emperor (193–211), founder of the Severus dynasty, was born; (d. February 4, 211). April 11, 491 — Flavius Anastasius becomes Byzantine emperor as Anastasius I. April 11, 1241 — Batu Khan’s Mongols destroy the Hungarian army led by King Bela IV in…