9 B.C.: Pagan Germanic tribes check advancing Romans in the Battle of the Teutoburg Forest, ending northward spread of Roman civilization, bounding the Roman Empire by the Danube and Rhine. c.700 A.D.
On Blood & Iron: The Rise and Fall of the German Empire, 1871–1918 by Katja Hoyer. It’s easy for modern commentators to regard the German Empire as no more than a violent chapter in European history.