Alexander Severus in Wikipedia

Marcus Aurelius Severus Alexander (1 October 208 – 18 March 235), commonly known as Alexander Severus, was Roman Emperor from 222 to 235. He was the last emperor of the Severan dynasty. Alexander Severus succeeded his cousin Elagabalus upon the latter's assassination in 222, and was ultimately assassinated himself, marking the epoch event for the Crisis of the Third Century - nearly fifty years of civil wars, foreign invasion, and collapse of the monetary economy. Alexander Severus was the heir apparent to his cousin, the eighteen-year-old Emperor who had been murdered along with his mother by his own guards-and as a mark of contempt, had their remains cast into the Tiber river. He and his cousin were both grandsons of the influential and powerful Julia Maesa, who had arranged for Elagabalus' acclamation as emperor by the famed Third Gallic Legion. A rumor of Alexander's death circulated, triggering the assassination of Elagabalus. As emperor, Alexander's peace time reign was prosperous. In military conflict against the rising Sassanid Empire, there are mixed accounts, though the Sassanid threat was checked. However, when campaigning against Germanic tribes of Germania, Alexander Severus apparently alienated his legions by trying diplomacy and bribery, and they assassinated him...

Link: https://en.wikipedia.org/wiki/Severus_Alexander