Gordianus III was just thirteen years old when he became sole Augustus of the Roman Empire. Since his grandfather and uncle, Gordianus I and II, had lost their lives when their rebellion had been quelled by Legio III Augusta, the new emperor decided to disband this legion. The legion would be reinstated again fifteen years later, but for now the only Roman legions in Africa were those in Egypt. The third legion may have been sorely missed, for in 240 the proconsul Sabinianus rebelled against his emperor. The rebellion was short-lived, mainly thanks to the efforts of the governor of Mauretania Caesariensis. Gordianus could now focus on the Romans’ most formidable enemy, the Sassanid Empire.
The Persian Giant
In 236 or 237, the Persian King Ardashir (Artaxerxes) had invaded the Roman province of Mesopotamia and had captured the cities of Carrhae, Nisibis and Edessa. Since the Romans did not respond in force, Ardashir was encouraged to attack again in 239. Now his target was Dura Europos, a city that had been founded by Macedonian settlers in about 300 BCE. The city had been part of the Parthian Empire since the 140s BCE, but it was captured by the Romans in 165. Dura was defended by the men of the Cohors XX Palmyrenorum, led by the tribune Julius Terentius. They may have been able to repel the attack, but their casualties were considerable and their commander was killed in battle.
The Persians did not just fight the Romans. In 240 or 241 the city of Hatra was captured. This was quite an achievement, as the city had withstood Roman sieges in 117, 198 and 199. The army that took Hatra may have already been commanded by Shapur I (Sapor in Roman sources), Ardashir’s talented son. He had recently been appointed co-ruler of the Sassanid Empire and would soon succeed his father, upon the latter’s death in 241 or 242. By now Gordianus was ready to respond to the Persian aggression. He had appointed a man named Gaius Furius Sabinius Aquila Timesitheus as his praetorian prefect and it would be Timesitheus who would take command of the Roman army in the East. The emperor had previously married his daughter Furia Sabinia Tranquillina. The other praetorian prefect was Gaius Julius Priscus, who would also participate in the emperor’s Persian campaign.
In 242 Gordianus formally opened the Gates of the Temple of Janus on the Forum Romanum to indicate that the Empire was at war with the Sassanids. The so-called Res Gestae Divi Saporis claim that the emperor “assembled from all of the Roman, Goth and German lands a military force”, which suggests that Gordianus took away troops from the Rhine and Danube borders. On his way to the East, the emperor campaigned in Moesia and Thrace, possibly against Sarmatian invaders. After a long journey, he reached Antiochia in Syria, one of the largest cities in the Empire. The Historia Augusta claims it had already been taken by the Persians, but there is no evidence they had ever captured it. In Antiochia the emperor, still just seventeen years old, and Timesitheus prepared for next year’s counteroffensive.
Victory and defeat
The Roman counterstrike launched in 243 was initially successful. Carrhae, Nisibis and Edessa were retaken and a Persian army was defeated, possibly in the vicinity of Resaena. Then disaster struck as Timesitheus suddenly died in autumn. The cause of death was probably disease and the ancient sources seem to agree that the man suffered from a bad case of diarrhoea. However, it was widely rumoured that his illness had been exacerbated by one Marcus Julius Philippus, who had tangled with the medicine that had been given to the prefect. It was not hard to suspect Philippus of foul play, as he would be nominated praetorian prefect next. Philippus happened to be the younger brother of Gaius Julius Priscus, the other prefect. Now for the first time in Roman history, two brothers held one of the most powerful offices in the Empire.
Although Shapur had withdrawn to Sassanid territory, Gordianus and Philippus decided to pursue their enemy. Their target was the city of Ctesiphon on the Tigris, the Persian capital. In early 244 the Roman and Persian armies clashed at Misiche (Mešīk or Μησιχη) and the result was a Persian victory. No details of the battle have survived and Shapur’s claim in his Res Gestae Divi Saporis that he had destroyed the Roman force were likely an exaggeration, but Gordianus had certainly suffered a defeat. Worse, he was soon dead at the tender age of nineteen (late February or early March). Shapur claimed the emperor had been killed on the battlefield, but it is more likely that he died afterwards. Perhaps Gordianus died of disease, like his father-in-law before him. Another possibility is that he was murdered by his infuriated soldiers. A third option is a conspiracy by the brothers Philippus and Priscus. Again, it is easy to suspect Philippus, as he would be named the next Augustus by the troops.
Marcus Julius Philippus – often called ‘Philip the Arab’ – now looked for ways to end the war against Shapur. The remains of the Roman army were trapped in Persian territory and their situation was therefore precarious. Since the king had him by the throat, Philippus’ only option was to negotiate. In exchange for 500.000 gold coins, Shapur was willing to make peace. Although the Romans lost no territory, the peace was still seen as a disgrace. The Persians kept Hatra, and Philippus had to accept that Armenia – in the past an eternal bone of contention between Rome and the Parthians – was in the Persian sphere of influence. All in all, Philippus’ reign had not started well.
- Historia Augusta, The Three Gordiani 23-31;
- Res Gestae Divi Saporis;
- Zosimus, Historia Nova, Book 1.16-19.
- Adrian Goldsworthy, The Fall of the West, p. 86-88, 92-94 and 475.
 The Historia Augusta also mentions a praetorian prefect named Maecius Gordianus, apparently a relative of the emperor (The Three Gordiani 30). It is not clear when he served as prefect.
 500.000 (silver) denarii according to the Res Gestae Divi Saporis, but historians agree the sum was paid in gold. See Adrian Goldsworthy, The Fall of the West, p. 475.