The number of fighters involved in the battle is not known for sure. Plutarch writes that the Romans were not outnumbered and had 40,000 men but that most were untrained and unaccustomed to weapons. Dionysius of Halicarnassus writes that the Romans had four well-trained legions and a levy of untrained citizens that was larger in number. That would give a rough figure of some 35,000. Diodorus Siculus writes that the Romans had 24,000 men. Livy gives no figures. The modern historians Cary and Scullard estimate that the Romans had 15,000 men and the Gauls 30,000 to 70,000. Peter Berresford Ellis gives an estimate of a minimum of 24,000 based on the assumption that "the Romans had... four legions – for each consul had two legions under his command – and given that each legion had 6,000 men". He also thinks that there may have been a contingent of allied troops. He thinks that the "Senones' tribal army could scarcely number more than 12,000".