The Battle of the Teutoburg Forest, also known as the Varian Disaster, was a significant event in history that took place near modern Kalkriese from September 8–11, 9 AD. This battle was between Germanic tribes and the Roman Empire. An alliance of Germanic peoples, led by Arminius, ambushed three Roman legions and their auxiliaries, which were led by Publius Quinctilius Varus. Arminius was a Germanic officer of Varus’s auxilia who had acquired Roman citizenship and received a Roman military education. His knowledge of Roman tactics allowed him to deceive the Roman commander methodically and anticipate the Roman army’s tactical responses. The Battle of the Teutoburg Forest is seen as one of the most important defeats in Roman history. It brought the triumphant period of expansion under Augustus to an abrupt end. The outcome of this battle dissuaded the Romans from their ambition of conquering Germania, and it is thus considered one of the most important events in European history. The provinces of Germania Superior and Germania Inferior, sometimes collectively referred to as Roman Germania, were subsequently established in northeast Roman Gaul, while territories beyond the Rhine remained independent of Roman control. Retaliatory campaigns were commanded by Tiberius and Germanicus and would enjoy success, but the Rhine would eventually become the border between the Roman Empire and the rest of Germania.