The Roman Empire was founded by Emperor Augustus in the 4th century BC until 395 and dominated the West and part of Asia for 4 centuries. The center of the empire was Rome, a city which from 100 BC to 400 AD was the largest in the world.
At that time, the population went from 50 to 90 million people and accounted for about 20% of the total population of the planet.
The official language was Latin, which left deep traces in the later European states, in the following centuries. Despite numerous problems, rivals and wars, the Romans managed to maintain the system for hundreds of years.
This came thanks to the application of these points.
military

One of the most powerful and organized armies of all time. Extraordinary efficiency was ensured by the organization in the legions. Rigorous training and great discipline gave the legions great maneuverability in formations supported by war machines during battle.
Roads

Roads connected more than 5 million square kilometers of the Empire. Goods were transported on the road network, which was mostly paved, but above all the legions passed very quickly. The construction of water pipes made it possible for the cities of the Empire not to depend on its lack, but to be autonomous.
Transportation

The Roman Empire ensured fast communication thanks to two public services. One was the curcus publicus, a service for imperial couriers on horseback that traveled 120 km a day. While the other "curcus velox" service for passengers.
Province

The empire was divided into provinces ruled by a governor. Subject peoples were integrated into the Empire through a subsidy treaty that gave them the right to cultivate the land in exchange for wartime military equipment.
town

Legions in the provinces, like all Roman military units, lived in camps. Resembling a fortified castle, the camps had a square plan, with streets perpendicular to each other. Some camps eventually became cities, such as today's Turin, Vienna and London.
Goths

The army was not formed on the basis of ethnicity. Volunteers born outside the Empire could also join the army. This turned the army into a powerful fighting machine where the skills and abilities of the warriors were mixed with each other. The Roman Empire also gave barbarian warriors the opportunity, if they deserved it, to take positions of responsibility.
Annona

Whoever lived in Rome was assured thanks to the existence of the "annona" (named after the Goddess of plenty): a supply of grain that guaranteed the poor citizens' survival. This decision was taken by Gaius Gracchus and served for popular support in the first steps of the empire.
aDOPTION

The practice of adoption was used for political purposes to form alliances. The system gained great importance during the imperial period. Adoption allowed, in effect, an emperor to choose his successor only from outside the circle of relatives.
religion

The Romans never fought religious wars. This was evidenced by the ancient ceremony organized in Rome. Deities were considered influential, honored with large temples in Rome. The purpose was to stop the enemies from protecting their gods, by "transferring" their gods to Rome, where they would have greater honor.
people

The male Roman citizen had a number of privileges: access to public office, participation in political meetings, benefits from a tax point. Citizenship, however, was not special for those who were Roman families. / Vox News