The Battle of the Teutoburg Forest, described as the Varian Disaster (Clades Variana) 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.