Dating back to the Roman era, Germania was the Latin name for a geographical area that stretched from the west bank of the Rhine to a vaguely-defined eastern frontier with the forest and steppe regions of modern Russia and Ukraine (Sarmatia), where Slavic tribes dominated.

Germania was inhabited by different tribes, mostly Germanic but also including some Celtic, Baltic, Slavic and Scythian, or steppe elements. Though Germanic tribes were in the majority, the ethnic makeup was complex and changed over the centuries as a result of assimilation and, most importantly, migrations. The Germanic people spoke Proto-Germanic dialects.

The classical world knew little about the people who inhabited the north of Europe before the second century BC. In the fifth century BC the Greeks were aware of a group they called Celts (Keltoi). Herodotus also mentioned the Scythians, but no other barbarian tribes. At around 320, Pytheas of Massalia sailed around Britain and along the northern coast of Europe, and what he found on his journeys were so unbelievable that later writers refused to believe him. He may have been the first Mediterranean to distinguish the Germanic people from the Celts. Caesar described the cultural differences between the Germanic tribesmen, the Romans and the Gauls. He said that the Gauls, although warlike, could be civilized, but the Germanic tribesmen were far more savage, and were a threat to Roman Gaul, and so had to be conquered. His accounts of barbaric northern tribes could be described as an expression of the superiority of Rome. The most complete account of Germania that has been preserved from Roman times is Tacitus' Germania.