Battle of Abritus
251 CE.
Shown on the map at 43.510°, 26.540°.
The Battle of Abritus also known as the Battle of Forum Terebronii occurred near Abritus (modern Razgrad) in the Roman province of Moesia Inferior in the summer of 251. It was fought between the Romans and a federation of Gothic and Scythian tribesmen under the Gothic king Cniva. The Roman army was soundly defeated, and Roman emperors Decius and Herennius Etruscus, his son, were both killed in battle. It was one of the worst defeats suffered by the Roman Empire against the Germanic tribes, rated by the Roman historian Ammianus Marcellinus as on par with the Battle of the Teutoburg Forest in 9, the Marcomannic invasion of Roman Italy in 170, and the Battle of Adrianople in 378. The emperors' deaths led to more political instability at Rome; and the loss of the army allowed repeated barbarian incursions in the region for the next two decades. The new Roman emperor Trebonianus Gallus was forced to allow the Goths to return home with their loot and prisoners. The barbarians would not be expelled from Roman territory until 271.
Text from the Wikipedia article Battle of Abritus, licensed CC BY-SA 4.0.