Founding of the Roman Empire

The Senate granted Octavian the title "Augustus", ending the Republic and beginning the Principate.

Having won the Mediterranean in the Punic Wars, Rome saw great estates (latifundia) spread and small farmers decline. After the reforms of the Gracchi brothers failed, an age of civil war followed in which powerful men fought each other with armies loyal to themselves. Caesar conquered Gaul and became dictator for life, but was assassinated by republicans in 44 BC.

Caesar’s adopted son Octavian allied with Mark Antony and then broke with him, defeating Antony and Cleopatra at Actium in 31 BC and annexing Egypt the following year. In 27 BC he made a show of handing his emergency powers back to the Senate, and the Senate gave him the title Augustus, "the revered one".

Augustus kept the institutions of the Republic but, calling himself princeps, "first citizen", held the army and the key provinces. This system is called the Principate. Some two hundred years of the Pax Romana followed, down to the age of the Five Good Emperors, as roads and Roman law bound the empire together. In this period Christianity arose in Palestine and spread along the empire’s routes.

After the crisis of the 3rd century Diocletian turned the system into the Dominate, an autocracy in which the emperor was revered almost as a god.