This introduction presents an overview of key concepts dicussed in the subsequent chapters of this book. Caesar Augustus or, more grandly, with the final cognomen leading, Augustus Caesar, was born on 23 September, 63 BC, as an Octavius, second child of a senator who was to reach the praetorship in 61, and was given his fathers praenomen of Gaius. The clan, which came from Velitrae, a Volscian town, claimed an ancient history, embroidered when the Octavii were raised to patrician rank by Julius Caesar: the tale took their original membership back to the time of the kings, before 509 BC. It was partly on account of the magnitude of Augustus achievement, but partly because of the notorious enigma of character he poses, that the idea of writing Augustus fictional autobiography appealed to the novelist Allan Massie. The enigma has been familiar since antiquity.