The Germanic Tribes
The Rhine-Danube areas were inhabited by several different Germanic tribes during the time of the Empire. They were clan-based, with blood-loyalty forming the basis for all bonds, and lived in settled forest clearings called hamlets, where they survived off of limited crops and animal products. There were no surpluses, so their population remained small—around one million. Without much occupational specialization, they were an Iron Age culture emphasizing war. In peacetime, tribal assemblies made up of all free men and warriors decided issues of peace and war. When war came, they would elect temporary war chiefs, whose legitimacy ended after hostilities.
Early Roman Relations with Germanic Tribes
The Germanic tribes were becoming an unavoidable issue for the Roman empire. Caesar had first observed them in 51 BCE during his time in Gaul, and from then on, their presence affected imperial policy. Despite the conflicts with Rome during the reign of Domitian, for the 1st century CE, Germanic tribes were not a real danger to Rome for several reasons. Not only did their poverty ensure poor armor and weaponry, but their tactics were limited. They were also divided into numerous small tribes, creating a lack of cohesion and cooperation, and had no form of central government.
Tacitus described the Germans again about 100 CE. Caesar’s conquest of Gaul had limited the range of nomadic tribes, causing demographic pressure along the borders. Some of these tribes began to come into contact with Roman civilization at border garrisons, with small numbers accepted into service with Roman legions. Small-scale Germanic-Roman trade relations also emerged, involving cattle and slaves, as the tribes greatly admired Roman arms and domestic wares.
Changes in the Germanic Tribes
Gradually, important changes in German tribes would occur over the next 250 years. Though kinship remained the primary bond, a new kind of political formation evolved: the Comitatus. Older, successful warrior chieftains took in younger warriors, who then raided and shared the booty with each other. This signaled the beginning of a small aristocracy, as bonds grew between man and lord. At the same time, tribes began electing fewer, longer serving war-chiefs as inter-tribe conflict increased, spurred by the desire to partake in Roman material culture. Around 200 CE, small tribes began to coalesce into larger groups, with several tribes migrating further south and putting more pressure on Roman borders.
It was the gradual, at times explosive, migration of Germanic tribes into Roman territory that would end the early peaceful years Marcus Aurelius' reign (161-180 CE). This demographic avalanche was not a result of hostility, but was simply a natural consequence of settled populations being neighbors with nomadic groups. Conflict between different tribes pushed this expansion as well, as each sought their own land.