As time went on, the Empire made changes to its military to reflect the its changing enemies as well as its new inabilities to find volunteers. This was also balanced against the respect for the classical models that had brought Rome to greatness and the political situation. Because the empire became unstable and prone to civil war many emperors increased the pay and benefits of the military or raised new forces when they thought the old ones were becoming too disloyal and political only to see their new forces slowly become political as well.
These changes included hiring more foreign soldiers as fewer and fewer Romans wanted to fight. These men sometimes were trained in the Roman fashion but at other times fought in their traditional way. Rome also started employing lighter infantry as well as greater numbers of cavalry and archers. This reflects the new military threats from more mobile nomadic enemies instead of the traditional heavy infantry enemies fighting with Hellenistic models. However, Roman military might was at its zenith around the reign of Augustus and it became relatively less and less effective compared to its neighbors.
These changes included hiring more foreign soldiers as fewer and fewer Romans wanted to fight. These men sometimes were trained in the Roman fashion but at other times fought in their traditional way. Rome also started employing lighter infantry as well as greater numbers of cavalry and archers. This reflects the new military threats from more mobile nomadic enemies instead of the traditional heavy infantry enemies fighting with Hellenistic models. However, Roman military might was at its zenith around the reign of Augustus and it became relatively less and less effective compared to its neighbors.