Europe 232: First Roman–Persian War
In 231 Ardashir I led the Persians into Roman Mesopotamia, prompting Roman emperor Severus Alexander to counter with a three-pronged invasion of Persia. However, as soon as his northern and southern armies were engaged on Persian territory, Alexander—who was to lead the vital middle army—abandoned the plan, leaving the other two armies to their destruction. Despite this, the damage caused by the Roman invasion convinced Ardashir to make peace, allowing Alexander to return to Rome in triumph.
228?–230? Ardashir I’s Eastern Campaign▲
Following his victory over Vologases VI (227/228), Shah Ardashir I returned to Istakhr, before setting out to conquer the eastern Parthian Empire. After suppressing Sakastan (in the southeast), Hyrcania, and Nishapur, he marched on Margiana, compelling its king (another Ardashir) to become a Sasanian vassal. From here he went back south to his newly completed capital at Gōr (Firuzabad), where he received envoys from the Kushans and Indo-Parthians.
230? Roman Thessaly▲
During the reign of Severus Alexander, the region of Thessaly was separated from Macedonia to form a new province, with its capital at Larissa. It was governed by an imperial procurator.
231–232 Ardashir I’s first Roman campaign▲
In 231 the Sasanian Persian shah Ardashir I crossed the Tigris into Roman Mesopotamia, overrunning the countryside and besieging Nisibis. When the Roman emperor Severus Alexander demanded that the Persians withdraw, Ardashir ignored him and continued to plunder the province. Upon hearing this, Alexander declared war, arriving in Syria with his army by early 232.
? ?? 231–25 Sep 233 First Roman–Sasanian War▲
In response to the Sasanian Persian invasion of Roman Mesopotamia, Severus Alexander traveled to Antioch, planning a three-pronged invasion of Persia: while one Roman force passed through the mountains of Armenia into Atropatene, a second force would cross the Euphrates into Babylonia, leaving an opening for Alexander to march his army down the Tigris between them. However, Alexander, listening to the fears of his mother Julia Mamaea, abandoned his part of the plan after the first and second armies were already committed, leaving them both to their destruction. Despite this, the damage caused by the Roman invasion convinced Shah Ardashir to call off his attacks, allowing Alexander to return to Rome in triumph.
As Severus Alexander arrived in Syria to deal with the Persian invasion of Roman Mesopotamia, numerous mutinies broke out among his troops. In Roman Mesopotamia itself, the legions killed their commander Flavius Heracleo and proclaimed a certain Taurinius as Emperor in 232. The revolt collapsed when Alexander reached the province in late summer and Taurinius drowned in the Euphrates while fleeing for Persia.