Publius (or Gaius) Cornelius Tacitus (ca. 56 - ca. 117) was a senator and a historian of the Roman Empire. The surviving portions of his two major works-the "Annals" and the "Histories"-examine the reigns of the Roman Emperors Tiberius, Claudius, Nero and those that reigned in the Year of the Four Emperors. Wikipedia
The definitive Wikipedia entry for Tacitus. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Tacitus