Much of what we know of as Europe, the nations that scatter that continent's map, was formed after ancient Rome fell and during its decline. Sometime around first or second century AD, the Roman army was over extended. Once they started retracting their units, the locals had to learn to protect themselves. There were some drawbacks to being under the protection of the Roman army, but one of the many benefits was that there was order and protection from foreign invasion and barbarian uprising. Once that protection was gone, the locals took charge, sometimes anarchy ensued, new tribes were formed and new boundaries were drawn.
It was right about this time that we start hearing about the German people. They were described as a fierce tribe of people who lived in a region with harsh weather. They were tall, had blue eyes, reddish blond hair and sternness in their gaze. When they went into battle, entire families would accompany them and would cheer from the side lines like we do now at sporting events. The most of what we know of these people come from the Roman scholar, senator and historian, Tacitus. In his book, Germania, (written around 98 AD), he describes them as an isolated nation of "noble savages" that had not mixed with the Roman empire, as the Nazis would later refer to as being "pure."
Copies of the book disappeared for centuries until the 15th century. It has been called one of the most dangerous books ever written. It was used to inspire the German invasion of Turkish land in the 15th century and more recently by Heimlich Himmler of the Nazi regime as a guidebook to resurrect Germany. Hitler found it so important he sponsored raids to seize copies of text. Many of the ideas promoted about the superiority of the German came right out of its text.
It is amazing to me how a text written by an ancient Roman senator in the first century AD indirectly affected millions of people in 20th century and possibly beyond.