The Roman army battled first against its tribal neighbours and Etruscan towns within Italy, and later came to dominate the Mediterranean and at its height the provinces of Britannia and Asia Minor. As with most ancient civilizations, Rome's military served the triple purpose of securing its borders, exploiting peripheral areas through measures such as imposing tribute on conquered peoples, and maintaining internal order. From the outset, Rome's military typified this pattern, and the majority of Rome's campaigns were characterised by one of two types. The first is the territorial expansionist campaign, normally begun as a counter-offensive, in which each victory brought subjugation of large areas of territory and allowed Rome to grow from a small town to a population of 55 million in the early empire when expansion was halted. The second is the civil war, which plagued Rome from its foundation to its eventual demise.