 The rebels had an efficient military organisation which paralleled that of the Romans, given that they had previously served in Roman-trained auxiliary military units.However, they did not have a regular army and relied largely upon guerrilla tactics, avoiding pitched battles.There were only three major battles in the area of Sirmium (Sremska Mitrovica, in modern Serbia), in nearby northern Moesia, and a number of minor battles in Dalmatia.