Roman battlefield found deep inside Germany

[MD]

Sorry to bring this up again, but does anyone have ideas as to what the Romans were doing so far up north? And with such a large army.. and in the 3rd century? It boggles the mind!

I mean, tentative punitive raids across the Rhine are one thing. A couple of legions traveling to Northern Germany armed to the teeth with scorpios and carrhoballistae is something else entirely...

Caracalla in 213 AD and later Maximinus Thrax in 235 campaigned personally against the Alamanni. Both had assembled large forces, including reinforcements from the east.

Especially Herodian's description of Maximinus campaign seems fit well with the location of the battlefield.

After leaving Mogontiacum and crossing the Rhine his first goal was probably to secure the Roman territories east of the river, the northern part of Agri Decumates. Then attacking the Germanic settlements near modern Kassel, which is just around 100 km away from the Wetterau, the most northern tip of Rome's territories east of the Rhine. The route was used regularly by Roman armies campaigning against the Chatti since Drusus times. If the Germans had deserted their settlements as described by Herodian, Maximinus could have decided to pursue them further north. Kalefeld is around 70 km away from Kassel, so only a few day marshes.

7.2: Maximinus' War against the Alamans

Having settled affairs in the manner described above, Maximinus led out his entire army and crossed the bridge fearlessly, eager to do battle with the Germans. Under his command was a vast number of men, virtually the entire Roman military force, together with many Moorish javelin men and Osrhoenian and Armenian archers; some were subject peoples, others friends and allies, and included, too, were a number of Parthian mercenaries and slaves captured by the Romans.

This enormous force was originally assembled by Alexander, but it was increased in size and trained for service by Maximinus. The javelin men and archers seemed to be especially effective against the Germans, taking them by surprise, attacking with agility and then retreating without difficulty.

Though he was in enemy territory, Maximinus advanced for a considerable distance because all the barbarians had fled and he met no opposition. He therefore laid waste the whole country, taking particular care to destroy the ripening grain, and burned the villages after allowing the army to plunder them. Fire destroys the German towns and houses very quickly.

...

The Germans had left the plains and treeless areas and were hiding in the forests; they remained in the woods and marshes so that the battle would have to take place where the thick screen of trees made the missiles and javelins of their enemies ineffectual and where the depths of the marshes were dangerous to the Romans because of their unfamiliarity with the region. The Germans, on the contrary, were well acquainted with the terrain and knew which places provided firm footing and which were impassable. They moved rapidly and easily through the marshes, in water only knee-deep. (The Germans, who do all their bathing in the rivers, are expert swimmers.)