To many inhabitants of the Roman Empire the army was the most visible representation of imperial power. Roman troops were the embodiment of imperial control. Military installations and buildings, the imperial guard, other troops, fleets, and militarily tinged works of art brought home the majesty of Rome to anybody who saw them, in Rome and in other parts of the Empire. With Roman armies came administrators, taxes and requisitions in cash and kind, traders, permanently residing veterans and military personnel, useful relations between local notables and Roman military cadre, and chances of upward social mobility. This sixth volume in the series Impact of Empire focuses on these topics.