Germany

It is ironic that the most serious threats to the Roman Empire began not with the western Germanic tribes of the Roman frontier but the eastern Germanic tribes, particularly the Goths. The Roman Empire during the early third century had a series of weak emperors and a strong challenge from the Parthian Empire of Persia. The resources of the Empire were debilitated and the Goths challenged the Romans for control of the area at the mouth of the Danube River at the Black Sea. The Goths controlled the area north of the Black Sea and the Romans had conquered a territory north of the Danube, which they called Dacia. This is the region of present day Romania.

The attacks of the Goths began in 247 A.D. and in 251 A.D. they lured the Roman army under the command of the Emperor Decius into a swampy region and defeated it. The Emperor Decius was killed in the battle. Emboldened by this victory the Goths built boats and ships and raided the cities of the Black Sea and eastern Mediterranean. The Romans under Claudius I finally were able to defeat the Goths decisively in 269 A.D. and brought peace to the region. The Emperor Claudius was thereafter known as Claudius Gothicus. But Claudius Gothicus' rule did not last long and he was succeeded by the Emperor Aurelian.

The Emperor Aurelian recognized the realities of the military situation in Dacia and in 270 A.D. withdrew Roman troops from Dacia leaving it to the Goths. The Danube once again became the northern frontier of the Roman Empire in eastern Europe. In 324 A.D. the Emperor Constantine concluded a treaty with the Visigoths that made them confederates of the Empire which meant that in return for annual subsidy