AUTHORITIES.--In addition to the _Report_ referred to above the following works may be consulted: H. T. Riley, _Memorials of London and London Life_ (1868); _Chronicle of London from 1089 to 1483_ (ed. by Sir N. H. Nicolas and E. Tyrrel, 1827); _Munimenta Gildhallae Londiniensis_, in Rolls Series, ed. by H. T. Riley (4 vols., 1859-1862); J. Toulmin Smith, _English Gilds_ (published by Early English Text Society), with essay by L. Brentano (1870); W. Herbert, _History of the Twelve Great Livery Companies_ (1837); C. Gross, _The Gild Merchant_ (2 vols., 1890); W. C. Hazlitt, _The Livery Companies of the City of London_ (1892), contains a précis of the Royal Commission; P. H. Ditchfield, _The City Companies of London_ (1904); G. Unwin, _The Gilds and Companies of London_ (1908). (T. A. I.) FOOTNOTE: [1] Properly the word should be spelled, as it was originally, "mistery;" it comes through the O. Fr. _mestier_, modern _métier_, from Lat. _ministerium_, service, employment, and meant a trade or craft, and hence the plays acted by craftsmen and members of gilds were called "mystery plays" (see DRAMA). For the word meaning a hidden or secret rite, with which this has so often been confused, see MYSTERY. LIVIA DRUSILLA (c. 55 B.C.-A.D. 29), Roman empress, was originally the wife of Tiberius Claudius Nero, by whom she had two sons, Drusus and Tiberius (afterwards emperor). But she attracted the attention of the future emperor Augustus, who in 38 compelled her husband to divorce her and married her himself, having first got rid of his own wife Scribonia. Her two sons, at their dying father's request, were entrusted to the guardianship of Augustus, to whom she bore no children. Livia was suspected of committing various crimes to secure the throne for Tiberius, whereas Augustus naturally favoured the claims of his blood-relatives. The premature deaths of his nephew Marcellus (whom he had at first fixed upon as his successor) and of his grandsons Gaius and Lucius Caesar, the banishment of his grandson Agrippa Postumus, and even his own death, were attributed to her. But in any case Augustus's affection for his wife appears to have suffered no diminution up to the last; by his will he declared her and Tiberius (whom he had adopted in A.D. 4) his heirs; Livia inherited a third of his property; she was adopted into the Julian gens, and henceforth assumed the name of Julia Augusta. The senate also elected her chief priestess of the college founded in honour of the deified Augustus. She had now reached the summit of her ambition, and at first acted as joint-ruler with Tiberius. Tiberius, however, soon became tired of the maternal yoke; his retirement to Capreae is said to have been caused by his desire to escape from her. Livia continued to live quietly at Rome, in the full enjoyment of authority, until her death at an advanced age. Tiberius