The Battle of the Teutoburg Forest, described as the Varian Disaster () by Roman historians, took place at modern Kalkriese in AD 9, when an alliance of Germanic peoples ambushed Roman legions and their auxiliaries, led by Publius Quinctilius Varus. The alliance was led by Arminius, a Germanic officer of Varus's auxilia. Arminius had acquired Roman citizenship and had received a Roman military education, which enabled him to deceive the Roman commander methodically and anticipate the Roman army's tactical responses. Teutoburg Forest is commonly seen as one of the most important defeats in Roman history, bringing 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 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. The Roman Empire would launch no other major incursion into Germania until Marcus Aurelius (r. 161–180) during the Marcomannic Wars. Some of the descendants of the vassal kingdoms, like the Suebi (by suzerainty), that Augustus tried to create in Germania to expand the romanitas and the Empire would be the ones that invaded the Empire in the fourth and fifth centuries. Background Geopolitical situation The Roman Republic had expanded rapidly in the first century BC, most notably under Julius Caesar, who had conquered most of western Europe and parts of the British Isles in the Gallic Wars (58–50 BC). The Gallic Wars mostly saw fighting against the Gauls, but had also included fighting against various Germanic tribes. Caesar had twice crossed the Rhine river to fight Germanic tribes, but the engagements were tactically inconclusive. The Gallic Wars effectively established the Rhine river as the northeastern border of the Roman Republic. Caesar's conquering spree was forced to an early end as Caesar's civil war (49–45 BC) drew near. Continental Europe was mostly forgotten about for the next two decades after the Gallic Wars as power struggles wracked the Republic. Troops which had previously garrisoned Gallic lands were pulled out in 31 BC for the climatic showdown