"The Lives of the Twelve Caesars, Complete" by Suetonius is a set of twelve biographies written in 121 CE. This ancient work chronicles the lives of Julius Caesar and the first eleven Roman emperors, from Augustus through Domitian. Suetonius served as personal secretary to Emperor Hadrian when he composed these intimate portraits. Drawing on official archives, personal letters, and contemporary accounts, he reveals the heritage, physical appearance, personal habits, and political careers of Rome's most powerful rulers during the Principate era.