The establishment of the Roman Empire marked the unification of the ancient world. For the first time, so many people, cultures and religions would co-exist under a single political institution. To manage this vast Empire, the Romans used military force, a highly developed legislation and efficient administration, which allowed a level of freedom to local populations. This led to a prolonged period of peace (Pax Romana), which was characterized by economic growth and intense interaction between the East and the West.
Technology developed tremendously, improving substantially the conditions of living (projects included the construction of roads, bridges, aqueducts, baths, theaters etc). At the time of Trajan and Hadrian (2nd c. AD), most Greek cities and sanctuaries were supported with infrastructure work and embellished with majestic buildings.
In the 3th c. AD, internal problems and external pressures led to the gradual destabilization of the Roman Empire. Significant part in this development was played by the rapid spread of monotheistic religions in the eastern provinces. In 313 AD the Edict of Mediolanum proclaimed religious tolerance across the Empire, and in 324 BC Emperor Constantine was baptized Christian. Foreseeing the importance of the Eastern part of the Empire, Constantine transferred the capital to the site of the ancient Megarian colony of Byzantium on the coast of Bosporus, which became known as “New Rome”.
| 27 BC | Octavian takes the title of Augustus – Establishment of Roman Empire |
| 49-56 BC | Apostle Paul travels in Greece – Establishment of first Christian communities |
| 98-117 BC | Emperor Trajan – greatest expansion of the Roman Empire |
| 117-138 BC | Emperor Hadrian – extensive iworks of infrastructure and embellishment in Greek cities and sanctuaries |
| 293 BC | Emperor Diocletian reforms the Roman Empire by dividing it in Eastern and Western part |
| 313 BC | Edict of Mediolanum |
| 330 BC | Foundation of Constantinople |
