The people of the Germans
If within the Roman State, the distances between the various peoples were reduced in proportion, however, generally deepen hostility toward foreign peoples. Hostilities with the Roman foreign policy outlined at the time of Augustus and remained substantially unchanged for five centuries until the fall of the Empire. Rome was forced to fight on two fronts: to the North had to fight against the Germans in the East against the Parthians. The Northern frontiers, established along the Rhine and Danube, excluded by the Germanic peoples.
The incursions of the barbarians, however, remained for the Romans always looming threat: "our town – Tacitus writes in his book Germany – was in its six hundred and forty eight year since its Foundation (i.e. in 113 BC) When for the first time we heard of the Cimbri.
Then they were consuls Caecilius Metellus and Papirius Carbo. From that year until the second consulship of the Emperor Trajan (i.e. in 97 ad) there are about two hundred years: how long have we to win the Germany! The Germans we celebrated many triumphs without ever actually beaten them. "
But who were the Germans, in which Tacitus saw the impetuous representatives of a free people and indomitable? They did not constitute a single nation, but a collection of Indo-European speaking tribes, settled mainly in the regions between the Rhine and the Elbe River and along the Danube; they don't ever, in ancient times, a national standard of living, but lived in scattered villages, in an area covered with forests and little suited to agriculture which offered minimum subsistence items.
For this reason, from time to time, Germanic peoples raiding tried crossing the borders Romans; or, as soon as possible, they serve as socii in the Roman army, which produced evidence of their courage and great military qualities, so much so that sometimes the personal guard of the emperors was recruited exclusively within them.
For the Romans, Germanic peoples, stationed beyond the limes were really "the other", i.e. the primitive that does not manage to civilize (i.e. "romanize") and which remained absolutely loyal to their ancient traditions, as well as insensitive to enticements of Greco-Roman civilization.
To counter the threat of the Germans were already in century a.d. to build a fortification system (the limes) that ran along the border and was garrisoned by the Roman army.
This had significant consequences from the demographic point of view and conditioned geography next: many Roman camps sprung up along the Rhine and the Danube were developed and gave rise to a city (including, for example, Cologne and Belgrade). In addition, many soldiers, after long years of service at the borders, once discharged established in those regions, which were then been romanized.