Though his work is the most reliable source for the history of his era, its factual accuracy is occasionally questioned: the "Annals" are based in part on secondary sources of unknown reliability, and there are some obvious minor mistakes (for instance confusing the two daughters of Mark Antony and Octavia Minor, both named Antonia). The "Histories", written from primary documents and personal knowledge of the Flavian period, is thought to be more accurate, though Tacitus's hatred of Domitian seemingly colored its tone and interpretations.