<P> Literacy was highly valued in the Roman military, and literacy rates in the military far exceeded that of the Roman society as a whole . </P> <P> Although early in its history troops were expected to provide much of their own equipment, eventually the Roman military was almost entirely funded by the state . Since soldiers of the early Republican armies were also unpaid citizens, the financial burden of the army on the state was minimal . However, since the Roman state did not provide services such as housing, health, education, social security and public transport that are part and parcel of modern states, the military always represented by far the greatest expenditure of the state . </P> <P> During the time of expansion in the Republic and early Empire, Roman armies had acted as a source of revenue for the Roman state, plundering conquered territories, displaying the massive wealth in triumphs upon their return and fueling the economy to the extent that historians such as Toynbee and Burke believe that the Roman economy was essentially a plunder economy . However, after the Empire had stopped expanding in the 2nd century CE, this source of revenue dried up; by the end of the 3rd century CE, Rome had "ceased to vanquish ." As tax revenue was plagued by corruption and hyperinflation during the Crisis of the Third Century, military expenditures began to become a "crushing burden" on the finances of the Roman state . It now highlighted weaknesses that earlier expansion had disguised . By 440 CE, an imperial law frankly states that the Roman state has insufficient tax revenue to fund an army of a size required by the demands placed upon it . </P> <P> Several additional factors bloated the military expenditure of the Roman Empire . First, substantial rewards were paid to "barbarian" chieftains for their good conduct in the form of negotiated subsidies and for the provision of allied troops . Secondly, the military boosted its numbers, possibly by one third in a single century . Third, the military increasingly relied on a higher ratio of cavalry units in the late Empire, which were many times more expensive to maintain than infantry units . </P>

Why did rome need to acquire new land through military expansion