The battle of Teutoburg forest was a pivotal moment in both German and Roman history. The battle would decide whether Germania would be colonized by the Romans or remain outside the Roman sphere of influence. The battle of a crushing loss for the Romans and the losses were so great it led to the deaths and destruction of three whole legions.
The battle of Teutoburg Forest was fought around 9 C.E. At this time, the Romans had conquered the western parts of Germania which would have included the modern day cities of Cologne and Trier. Publius Quinctilius Varus was made governor of the Roman province of Germania to consolidate the lands and start building cities and establishing infrastructure in the new Roman province. During this time Varus had taken on a Roman educated Germanic warlord by the name of Arminius in order to use him to try and forge peaceful relations with the Germanic tribes still outside Roman influence. Little did Varus know but Arminius made secret deals with the Germanic tribes he was supposed to make peaceful relations with to destroy Roman power in Germania. Arminius then gave Varus a false report of a major Germanic uprising requiring Varus's immediate attention. In order to get to the site of the rebellion quickly Varus decided to pass through unfamiliar Germanic territory using Arminius as a guide because he was familiar with the territory. Arminius then led Varus and his legions to Teutoburg forest right where the combined Germanic tribes were waiting for him. Arminius then left the Roman legions with his men, officially to drum up more Germanic support for the Roman campaign, but unofficially to attack Roman forts and abandon Varus and the legions to the Germanic tribes. Varus was now trapped in hostile territory surrounded by Germanic tribes that hated Romans and were led by a Germanic warlord who was taught Roman tactics.
At the beginning of the battle, Varus had three Roman legions and a fair collection of auxiliaries and calvary.