The Roman Empire Hadrian inherited from Trajan in 117 CE was at its political and social peak. It was the largest empire in western civilization and covered a swathe of territories, extending from Britannia to Mesopotamia. The empire had begun life as a republic and was greatly extended under Julius Caesar (100–44 BCE) who added modern France and Belgium to its territories while governor of Roman Gaul. Eventually, Caesar was made dictator for life although he served only one year before his assassinations. The Roman Republic became Imperial Rome under Caesar Augustus, Caesar’s adopted heir (27 BCE–19 CE). Augustus quelled rebellions and restored firm Roman control to imperial provinces, extending the frontier through central and eastern Europe. By 117 CE, Trajan had enlarged, and restored control, to many Roman imperial provinces. Since the rule of Augustus, provinces had been divided between the rule of the Senate and the Emperor. The Senate controlled the more secure provinces towards the centre of the empire where they were able to select governors, whereas the Emperor controlled the peripheral provinces where more militaristic leaders were required. Under Trajan the Dacian Kingdom and parts of the Parthian Empire in Armenia were invaded and brought under the control of Emperor..
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