Gaius Suetonius Tranquillus (Latin: [ˈɡaːiʊs sweːˈtoːniʊs traŋˈkᶣɪlːʊs]), commonly referred to as Suetonius ( swih-TOH-nee-əs; c. AD 69 – after AD 122), was a Roman historian who wrote during the early Imperial era of the Roman Empire. His most important surviving work is a set of biographies of 12 successive Roman rulers from Julius Caesar to Domitian, properly titled De vita Caesarum. Other works by Suetonius concerned the daily life of Rome, politics, oratory, and the lives of famous writers, including poets, historians, and grammarians. A few of these books have partially survived, but many have been lost. Source: Wikipedia (en)