Cassius Dio was born in Nicaea (Bithynia-Pontus) in about AD 163. Dio's father was a rich man who later became a governor of the Roman province of Cilicia.
In AD 180 Cassius Dio moved to Rome. When Septimius Severus arrived in Rome he sent him a pamphlet which foretold Severus' rise to power. He became a friend of the emperor and was a member of his advisory council.
Dio spent twelve years writing his book Roman History. The book starts with the foundation of Rome and ends with the death of Emperor Septimius Severus in AD 211. Like most Roman historians Dio concentrates on the main political and military events and rarely writes about social and economic developments. In his work Dio reveals that he was a strong supporter of dictatorial rulers such as Augustus.
The rousing of the Britons, the persuading of them to fight against the Romans, the winning of the leadership and the command throughout the war - this was the work of Boudicca, a woman of the British royal family who had uncommon intelligence for a woman... When she had collected an army about 120,000 strong, Boudicca mounted a rostrum... She was very tall and grim... and her voice was harsh. She grew her long auburn hair to the hips. Taking a spear too to add to her effect upon the entire audience.
Cleopatra had, it was believed, enslaved Mark Antony... that she had laid him under some spell and deprived him of his wits... She came to entertain the hope that she would rule the Romans as well as the Egyptians... The Romans were willing to believe that Antony would hand over the city of Rome to Cleopatra and transfer the seat of government to Egypt.