Below, you can see the Balkan portion of the Roman empire. Constantinople’s location near the Danubian frontier allowed the emperor to quickly respond to threats from that direction, but it also put the capital at risk.

To strengthen the empire’s Balkan defenses, Constantine pushed his armies beyond the Danube, defeated the Sarmatian Iazyges and the Germanic Goths, and created two buffer provinces: Sarmatia and Gothia. He also subjugated the Gothic tribes inside the Carpathian arc, and though those peoples still had autonomy, they were subject to the empire.

If we focus on the lands of the original province of Dacia, we see that Gothia was located between the Carpathian Mountains and the Danube River. The territory was protected by a defensive line of earthen ramparts and ditches punctuated by forts, which was staffed by both Roman soldiers and Gothic warriors.

The new province of Gothia included the city of Sucidava, which had remained under imperial control even after the abandonment of Dacia, and which now hosted a permanent stone bridge across the Danube.

The province also included the city of Malva, which had been abandoned during Aurelian’s retreat but which continued to house a population of Roman descendants; the army repaved the road between Malva and Sucidava, and so connected that settlement to the rest of the empire.