Maximinus Thrax was a military man all his life and is considered the first barracks emperor (or soldier emperor). He spent most of the rest of his career as emperor campaigning along the Rhine and Danube, protecting the northern border of the Roman Empire. The Senate grudgingly accepted him as Augustus, but secretly despised him because of his low birth and barbarian background. Some senators may have been involved in a plot to kill him soon after he took control of the state.
The plot was allegedly hatched by a senator and former consul named Magnus, who was from an old and noble family. The emperor was still in his camp near the Rhine and was about to cross a ship bridge that had been constructed for Alexander’s campaign into Germanic territory. Magnus had reportedly persuaded a small detachment of soldiers to break down the ship bridge after the emperor had crossed it, so that he would be trapped in enemy territory and would be left to the enemy’s mercy. It is impossible to say whether or not there was such a plot. Maximinus may have made it up himself to get rid of some political opponents of senatorial rank. In any case, he “discovered” the plot and had all the suspects arrested and killed. A formal investigation and trial were never held, and as many as 4.000 people may have been murdered.
Soon the emperor had to deal with a rebellion among his Osroenic archers, who still felt much sympathy for Alexander and were deeply angered by his death. They managed to find a man of consular rank, a friend of Alexander named Quartinus, and proclaimed him emperor. Quartinus was soon killed however, and his head was brought to Maximinus. The rebellion among the archers now quickly petered out. Maximinus presumably got them back on his side as Herodianus tells us that archers from Osroene accompanied the emperor on his campaigns against the Germanic tribes.
Campaigns against the Germanic tribes
It was now the summer of 235 and Maximinus finally launched his invasion of Germania. He marched his army across the ship bridge and soon found himself in enemy territory. The Germanic tribes tried to avoid confrontations with the Roman army and pulled back their forces as soon as the Romans came within sight. The emperor penetrated hundreds of kilometres into enemy territory, a claim that is backed up by both literary and archaeological evidence.
The Historia Augusta claims that “he burned villages, drove away flocks, slew numbers of the barbarians themselves, enriched his own soldiers, and took a host of captives” over a distance of 300 or 400 miles. A Roman mile is 1.479 metres, so Maximinus is claimed to have covered a distance of some 440-590 kilometres. This was long thought to be a massive exaggeration and the text of the Historia Augusta was usually corrected to 30-40 miles. However, excavations at the Harzhorn in Niedersachsen, Germany, have uncovered the site of a battle between Romans and Germanic warriors which may have taken place around 230. The location of the battlefield is some 300 kilometres northeast of Mogontiacum, where Maximinus started his invasion.
The emperor always fought in the front ranks and showed many deeds of great bravery. But by doing so, he also put himself and the future of the empire in great danger. The Germanic warriors avoided open battle and instead tried to lure the Romans into the swamps and forests, where they knew the terrain well and their adversaries did not. Herodianus writes that:
“When the Germans rushed into a vast swamp in an effort to escape and the Romans hesitated to leap in after them in pursuit, Maximinus plunged into the marsh, though the water was deeper than his horse’s belly; there he cut down the barbarians who opposed him. Then the rest of the army, ashamed to betray their emperor who was doing their fighting for them, took courage and leaped into the marsh behind him. A large number of men fell on both sides, but, while many Romans were killed, virtually the entire barbarian force was annihilated, and the emperor was the foremost man on the field. The swamp pool was choked with bodies, and the marsh ran red with blood; this land battle had all the appearance of a naval encounter.”
The Crisis of the Third Century
Maximinus sent reports of his successful campaigns to the Senate and People of Rome. He also had paintings of his actions made and had them placed in front of the Senate House. The emperor now chose Sirmium in Pannonia (today’s Sremska Mitrovica in Serbia) as his de facto capital and used it as a base for his operations against the Dacians and Sarmatians in 236 and 237. In either 236 or 237, the Persian King Artaxerxes invaded Mesopotamia again and captured Carrhae, Nisibis and Edessa. Maximinus was a cruel and oppressive ruler, if we are to believe our sources. He had a bad relationship with the nobility in Rome, and the nobility in turn hated its emperor and thought of ways to get rid of him. Civil war was looming again and the Crisis of the Third Century had begun.
– Adrian Goldsworthy, The Fall of the West, p. 92.