"The concept of Germany as a distinct region in central Europe can be traced to Roman commander Julius Caesar..."

"... who referred to the unconquered area east of the Rhine as Germania, thus distinguishing it from Gaul (France), which he had conquered...."

In the first years of the 1st century, Roman legions conducted a long campaign in Germania, the area north of the Upper Danube and east of the Rhine, in an attempt to expand the Empire's frontiers and shorten its frontier line. They subdued several Germanic tribes, such as the Cherusci. The tribes became familiar with Roman tactics of warfare while maintaining their tribal identity. In 9 AD, a Cherusci chieftain named Arminius defeated a Roman army in the Battle of the Teutoburg Forest, a victory credited with stopping the Roman advance into Germanic territories and forming the birth of German history....

Much more happens in Germany, today's "History of" country.