Viriatus developed alliances with other Iberian groups, even far away from his usual theatres of war, inducing them to rebel against Rome. He led his army, supported by most of the Lusitanian and Vetton tribes as well as by other Celtiberian allies, to several victories over the Romans between 147 BC and 139 BC before being betrayed by them and murdered while sleeping. Of him, Theodor Mommsen said, "It seemed as if, in that thoroughly prosaic age, one of the Homeric heroes had reappeared."