M. Aurelius Severus Slexander, originally named Alexianus, was born about AD 208, the son of Julia Mamaea and Gessius Marcianus. In 221 he was adopted by Elagabalus, his cousin, and given the title of Caesar. After the murder of Elagabalus, Alexander was at once acknowledged as Emperor by the Praetorian guards, the senate giving its confirmation the following day.
Alexander ruled the empire wisely and well and the condition of the state was much improved, but the emperor was very much under the influence of his mother, and this was greatly resented by the army. For the first nine years of the reign the empire was untroubled by foreign wars, but in 232 Alexander had to take the field against the Sassanid Ardashir who had recently overthrown the Arsacid Kingdom of Parthia and who was now threatening Syria and Cappadocia. This campaign met with only partial success and Alexander soon had to return to the west where disturbances on the German frontier necessitated his presence. However, before the fighting actually began the soldiers proclaimed Madiminus, one of their commanders, Emperor, and Alexander and Julia Mamaea were murdered at their camp near Mainz on March 22, 235 AD.