The "Annals" was Tacitus's final work and he wrote it in at least 16 books, but books 7-10 and parts of books 5,6,11 and 16 are missing.
The "Annals" was Tacitus's final work, covering the period from the death of Augustus Caesar in the year 14. He wrote at least 16 books, but books 7-10 and parts of books 5,6,11 and 16 are missing.