Following World War II, democratic Italy officially abolished titles and hereditary honours in its Constitution and ceased having an official governing body of nobility headed by the state. Titles bestowed after 28 October 1922 (i.e. after the rise to power of Fascism) were declared never to have existed. Only those families bearing older titles were permitted to use them. These laws did not apply to the nobility of Rome, insofar as they had been created by the Pope, when he was a sovereign head of state (i.e. until 20 September 1870). After a period of uncertainty, the Italian aristocracy continued to use their titles in the same way as they had in previous centuries. This behaviour was cemented by the continued publication of Il Libro d'Oro della Nobiltà Italiana, published as much to prevent self-styled aristocrats social climbing as to list the established nobility.
The Libro d'Oro della Nobiltà Italiana (Golden Book of the Italian Nobility) is regularly published by the Collegio Araldico of Rome. It lists some of Italy's noble families and their cadet branches. First published in 1910, it includes some 2,500 families, and may not be considered exhaustive. Included are those listed in the earlier register of the Libro d’Oro della Consulta Araldica del Regno d’Italia and the later Elenchi Ufficiali Nobiliari of 1921 and of 1933. The Libro d'Oro should not be confused with a social register - wealth, status and social contacts are of no consideration on the decision as to whether a person may be included in the book, the only consideration is the blood or marital relationship to the head of a noble family. Nor is it a peerage reference such as those published in Great Britain. The currently published Libro d'Oro is not an official publication of the Italian state, which currently does not have a civic office to recognise titles of nobility or personal coats of arms. The most recent (24nd) edition of Libro d'Oro della Nobiltà Italiana was published in September 2010.
In addition to the Libro d'oro of Venice, such books had existed in many of the Italian states and cities before the unification of Italy. For example, the Libro d'Oro of Murano, the glass-making island in the Venetian Lagoon, was instituted in 1602, and from 1605 the heads of the Council of Ten granted the title cittadino di Murano to those heads of families born on the island or resident there for at least twenty-five years. A Libro d'Oro was also compiled on each of the Ionian Islands as a nobiliary of the members of local Community Councils (Zante 1542, Corfu 1572 and Cephalonia 1593)
In the reformed Republic of Genoa of 1576 the Genoese Libro d'Oro, which had been closed in 1528, was reopened to admit new blood.
By extension, a Libro d'Oro is a by-name for any nobiliary directory, as when Al. N. Oikonomides refers to "the recently published 'libro d'oro' of the wealthy ancient Athenians (J.K. Davies, Athenian Propertied Families 600-200 B.C. (Oxford 1971)".
See also 
- Heraldry in Italy.
- Collegio Araldico
- V. Zanetti, Il libro d'oro di Murano, (Venice: Fontana) 1883, noted by Francesca Trivellato and Maria Novella Borghetti, "Salaires et justice dans les corporations vénitiennes au 17e siècle: Le cas des manufactures de verre", Annales. Histoire, Sciences Sociales 54.1 (January - February 1999:245-273) p. 253 note 18.
- Rizo-Rangabè, Eugène: "Livre d'Or de la Noblesse Ionienne", Volumes 1-4, Athens 1925-6-7
- Moschonas, Nikos G.: "Records of the Community Council of Cephalonia - First Book 1593", Athens 1979 (extract)
- Zaridi, Katerina F.: "The Libro D'Oro of Cephalonia of the Year 1799", Argostoli 2006 (in Greek)
- Cangelaris, Panayotis D.: Libro d'Oro - The Golden Book of Cephalonia, Corfu 2011 (extract)
- Al. N. Oikonomides, "Aristoteles, the Son of Opsiades and Polystrate" The J. Paul Getty Museum Journal 5 (1977:41-42) p.