Gaius Suetonius Tranquillus, better  known as Suetonius (ca. 69/75 – after 130), was an Ancient Roman historian during who lived at a time when the Roman Empire was still relatively new. He wrote about the daily life in Rome, politics, and biographies of famous poets and other historians. But he’s best remembered for his biographies of the Twelve Caesars, starting with Julius Caesar and ending at Domitian. De vita Caesarum, Latin for “On the Life of the Caesars,” is better known as The Twelve Caesars. Suetonius wrote it in 121 A.D. at the height of the reign of Hadrian. Suetonius was apparently Hadrian’s secretary, but the frequently traveling emperor apparently provided Suetonius enough down time to put in a serious amount of research at Rome’s imperial archives to study the lives of the Caesars. De Illustribus Grammaticis ("Lives Of The Grammarians"); is Suetonius’ small biography covering 20 brief lives of Rome’s best grammarians. It seems to have survived in complete form, unlike much of Suetonius’ work.