Ancient Greeks distinguished between three different types of friendships between two polities: Philiai, symmachia, and epimachia. Both symmachia and epimachia were types of alliances, with the former committing States to support each other in battle and the latter requiring parties to assist each other if one suffered an invasion. Philiai, then, made the important distinction of denoting friendship between polities but did not give the treaty partners the status of allies. Romans had a similar word amicitia, which was a state of diplomatic relations which could coexist with an alliance, or exist without it. The Romans employed a practice of establishing peace and friendship with polities on its peripheries, though in practice these relationships were usually built on unequal treaties, requiring the neighbour to support Rome militarily, though not necessarily the reverse.[