229. Dion Cassius having, as governor of Dalmatia and Pannonia, offended the army by his strictness, the Emperor testifies his approbation by making him his colleague in the consulship.
230. Artaxerxes, now at the head of a powerful empire and great army, lays claim to all the former territories of Persia.
231. Alexander Severus, at Antioch, prepares to resist the Persian demands by arms.
232. After a campaign in Mesopotamia without decisive results, but in which the Romans claim the victory, Alexander returns to Antioch.
233. Close of the Persian war.
234. Alexander musters his forces in Gaul to repel the German tribes that had invaded the province.
235. Alexander Severus and his mother, Mamæa, are murdered in a mutiny of the army, near Mainz (or Mentz).
Maximin is proclaimed emperor.
Ambrosius assists the labors of Origen by paying clerks to copy for him.
236. Maximin defeats the Germans and drives them across the Rhine.