Roman Empire

The Roman Empire was the post-Republican period of the ancient Roman civilization, characterized by government headed by emperors, and large territorial holdings around the Mediterranean Sea in Europe, Africa, and Asia. The 500 year old republic which preceded it was severely destabilized in a series of civil wars and political conflict, during which Julius Caesar was appointed as perpetual dictator and then assassinated in 44 BC. Civil wars and executions continued, culminating in the victory of Octavian, Caesar's adopted son, over Mark Antony and Cleopatra at the Battle of Actium in 31 BC and the annexation of Egypt. Octavian's power was now unassailable and in 27 BC the Roman Senate formally granted him overarching power and the new title Augustus, effectively marking the end of the Roman Republic.
The imperial successor to the Republic endured for some 500 years. The first two centuries of the Empire's existence were a period of unprecedented political stability and prosperity known as the Pax Romana, or "Roman Peace". Following Octavian's victory, the size of the Empire was dramatically increased. After the assassination of Caligula in 41, the Senate briefly considered restoring the republic, but the Praetorian Guard proclaimed Claudius Emperor instead. Under Claudius, the Empire underwent its first major expansion since Augustus. After Claudius' successor, Nero, committed suicide in 68, the Empire suffered a period of brief civil wars, as well as a concurrent major rebellion in Judea, during which four different legionary generals were proclaimed Emperor. Vespasian emerged triumphant in 69, establishing the Flavian dynasty, before being succeeded by his son Titus, who opened the Colosseum shortly after the eruption of Mt. Vesuvius. His short reign was followed by the long reign of his brother Domitian, who was eventually assassinated. The Senate then appointed the first of the Five Good Emperors. The Empire reached its greatest extent under Trajan, the