German military history

While German-speaking people have a long history, Germany as a nation state dates only from 1871. Earlier periods are subject to definition debates. The Franks, for instance, were a union of Germanic tribes; nevertheless, some of the Franks later identified themselves as Dutch, Flemish, French and again others as Germans. The capital of medieval ruler Charlemagne's empire was the city of Aachen, now part of Germany, yet he was a Frank. France was named after the Franks and the Dutch and Flemish people are the only ones to speak a language that descends from Frankish (the language of the Franks). Hence nearly all continental Western European historians can claim his victories as their heritage. The Holy Roman Empire he founded was largely but far from entirely German speaking. The Kingdom of Prussia, which unified Germany in the 19th century, had significant territory in what is now Poland. In the early 19th century, the philosopher Schlegel referred to Germany as a Kulturnation, a nation of shared culture and political disunity, analogous to ancient Greece. Until the unification of 1871, Austria was considered a part of Germany even though much of its empire was not in the Holy Roman Empire and was non-German.

During the ancient and early medieval periods the Germanic tribes had no written language. What we know about their early military history comes from accounts written in Latin and from archaeology. This leaves important gaps. Germanic wars against the Romans are fairly well documented from the Roman perspective, such as the infamous Battle of the Teutoburg Forest. Germanic wars against the early Celts remain mysterious because neither side recorded the events.

...
Wikipedia