Described as one of the largest empires in our known history the Roman Empire dominated throughout Europe and considered itself an empire without end.
There were 3 components of the Imperial Roman state those being the military, their central government and the provincial government.
The military would gain territory by means of war and after they conquered they would turn their mission into a police state making sure Roman citizens were not harmed.
The military could not maintain control with such vast territory so they would rely on cooperation of the local elite to gather taxes, control their people and would gather information critical to maintaining control.
The Imperial Roman Army was a full time career made up of soldiers who would volunteer for twenty years of service. Their task was to operate the three divisions of the military which included the navy, the provincial army and the garrison in Rome.
The tax laws under the Roman Empire were very complicated, some taxes required cash payment others in kind (same as a barter system) the amount was approximately 2-5 percent for individuals and 5 percent for the gross products of the Empire.
The tax collection was justified to support the military and some even had an expiration date and some would be different for any given province.