Rising overhead costs, with no corresponding growth of income, an empty treasury in Rome, and a persistent policy of fleecing the provinces to pay for the normal costs of bureaucracy, plus its extravagances and excesses, could lead to only one possible outcome.  Higher taxes and more ruinous levies in the newly conquered provinces could not fill the insatiable maw of deficit spending.

Inflation was the immediate result, accompanied and followed by the debasement of currency and new expropriations of private property.  Government expenses consistently exceeded income.  The situation was aggravated by the growth of parasitic elements which persistently produced little or nothing and as persistently multiplied their luxuries and extravagances.  The parasites grew richer.  The impoverished masses suffered the normal deprivations of poverty plus the weight of steadily rising over-head costs.  As Roman authority extended farther from its center, the chasm between its income and its out-go widened.

Slave labor aggravated the situation.  There was a time when Roman farmers and craftsmen did their own work.  That time ended with the enslavement of war captives who swamped the labor market.  Like any parasitic growth, slavery and forced labor destroyed the fabric of a largely self-contained economy based on peasant proprietorship.

Roman economy was honey-combed with problems created by deficit spending, currency devaluation and exploitation.  At its base was a foot-loose urban proletariat made up largely of refugees from a countryside given over increasingly to the employment of military captives as slave labor.  The city masses at the outset were extensively unemployed.  Increasingly they became unemployable, parasitic, restless, demanding.

At the outset the slave revolts were local and occasional.  As the slaves grew more numerous unrest spread and hardened into organized resistance.  Spartacus, a slave, led a revolt which mobilized armies, defeated the Roman legions in a series of battles and ended only with the death of Spartacus and the dispersal of his forces.

Local and provincial affairs under the Roman Empire were administered by a self-seeking corrupt bureaucracy.

Expansion by means of military conquest increased the influence of the military at the expense of the civilian administrators.  The consequent burdens of militarism reached from the bottom to the top of Roman society.  Eventually, under the Caesars, the military selected emperors from among the rivals for the purple of imperial authority, and used the legions under their command to protect and promote their own political fortunes, thus maintaining a form of latent and frequently open civil war.

Colonial unrest and provincial self-seeking were promoted by conspiracies among Rome’s less dependable allies.

Wars of rivalry between Roman candidates for top preferment shifted the power-balance out of civilian hands into the grip of the military.  Step by step and stage by stage the Roman Empire became a warfare state maintained at home and abroad by the intervention of the military.  Wars of rivalry at home in Rome were paralleled by wars of rivalry abroad.