The expansion of the Roman Empire was based on both the advent of roads and development of advanced water systems. Rome also permitted the people they defeated in war to govern themselves as long as they remained loyal to Rome.
The Roman Empire was able to expand through much of Europe due to the superior technology of its road-building systems. Roads such as the Appian Way in Italy helped Rome to reach interior portions of various territories. In addition to the Roman Navy, which was essential in conquest, the development of underground water transport and above-ground aqueducts, which were based on Greek technology, enabled Rome to move water. Remnants of Roman water systems are still evident as far away as France. Rome developed a confederacy by granting citizenship to defeated people groups, such as those in Taras.