The Battle of Teutoburg, that took place in 9 AD, shook the Roman empire. The battle was actually a very clever ambush by the Germanic tribes under the leadership of Arminius, who was a tribal leader. 10,000 tribesmen slaughtered about 20,000 to 25,000 Roman soldiers and routed 3 legions. Another important battle, the Battle of the Weser River, took place under the leadership of Arminius, in 16 AD.