Federal glass dating
Under Augustus, Rome began to invade Germania (an area extending roughly from the Rhine to the Ural Mountains).
In 1871, Germany became a nation state when most of the German states unified into the Prussian-dominated German Empire.
By 100 AD, when Tacitus wrote Germania, Germanic tribes had settled along the Rhine and the Danube (the Limes Germanicus), occupying most of the area of modern Germany.
However, Austria, Baden Württemberg, southern Bavaria, southern Hessen and the western Rhineland had been conquered and incorporated into Roman provinces: Noricum, Raetia, Germania Superior, and Germania Inferior.
Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity.
A region named Germania was documented before 100 AD.