In 390 BC a Gaulish warband first defeated the Roman army at the Battle of the Allia and then sacked Rome. The ancient writers report that in 389 the Etruscans, the Volsci and the Aequi all raised armies in hope of exploiting this blow to Roman power. According to Livy the leading men of all of Etruria gathered at the sanctuary of Voltumna to form a hostile alliance against Rome. Beset by dangers on all sides, the Romans appointed Marcus Furius Camillus dictator. Camillus chose to march against the Volsci first, leaving, according to Livy, a force commanded by consular tribune L. Aemilius Mamercinus in the Veientine territory to guard against the Etruscans. In the course of two campaigns Camillus inflicted crushing victories against the Volsci and the Aequi and was now ready to take on the Etruscans.