Severus Alexander

Severus Alexander (208–235) was Roman emperor from 222, the last of the Severan dynasty and, at thirteen, the empire's youngest sole emperor. A grandson of Julia Maesa, he was adopted by his unpopular cousin Elagabalus; she then arranged Elagabalus's murder, and the guards hailed him that March.

He relied on Maesa until her death in 224, and thereafter on his mother Julia Mamaea, from whom he got the nickname Mamaeas. His senatorial council included the jurist Ulpian, but the praetorians murdered him before Alexander could intervene.

After Ardashir founded the Sassanid dynasty, he checked raids by the Persians in Mesopotamia. When Germanic tribes crossed the Rhine and Danube he camped at Mainz and tried bribing them into peace, enraging soldiers who wanted loot. In March 235 they killed him and Mamaea, probably in a mutiny led by the Thracian officer Maximinus, who took the throne; decades of crisis followed.