Who served in the Roman army? This simple question has a wider significance, since the social, economic and legal status of Roman soldiers, and the nature of the military community, can help us understand what inspired and motivated these men to fight for Rome under the emperors. The psychology of men in battle, and the morale and resilience of armies, sometimes against impossible odds, are complex issues. For the ancient world we usually lack detailed battle descriptions, or the memoirs and letters of individual soldiers on both sides of the conflict which are so valuable for vividly bringing to life battle experiences. However, despite obvious differences in weaponry and military organization, the factors that influence the morale of soldiers have remained pretty constant, and the methods of analysing warfare in other ages are therefore relevant. 1
At various stages in its history the Roman army comprised a militia, citizen-soldiers, mercenaries and professional troops, both conscripts and volunteers, although there was no clear linear development. 2 The earliest Roman army will have consisted of the king, his retainers, nobles and whatever clan members could be organized to fight, largely in raids against neighbouring communities. This was a citizen militia habituated to seasonal warfare, in which we may guess that soldiers were motivated by ideas of survival, self-defence and patriotism. By protecting themselves, their families and their smallholdings, they also ensured the survival of the Roman state. Of course, peer pressure will also have been important, as they saw other small farmers in the ranks with them.
As Rome developed politically and militarily, the will of the upper classes usually prevailed in decisions on war and peace, and the government regularly conscripted its citizens, though preferring those who could equip themselves. 3 This, however, did not mean that the Roman people were unwilling soldiers. On the contrary, they were apparently quite belligerent. The levy for Rome’s legionary army around the mid-third century BC