The Annals was Tacitus' final work and provides a key source for modern understanding of the history of the Roman Empire from the beginning of the reign of Tiberius in AD 14 to the end of the reign of Nero, in AD 68. Tacitus wrote the Annals in at least 16 books, but books 7–10 and parts of books 5, 6, 11 and 16 are missing.WIKI