From 1105 to 1914, the diocese was merged with the Suburbicarian Diocese of Velletri. In 1962, the Diocese of Ostia was brought under the direct administration of the Diocese of Rome.
The Cardinals of the Holy Roman Church – Guide to documents and events (76–2005) This statement of Miranda is unsourced. Moreover, Rudolf Hüls (pp.79–80) has demonstrated that the perpetual leadership of the Bishop of Ostia is not the case, but that the principle of seniority held true in Rome as it did elsewhere (cf. Hüls, pp. 77–78), before and after Pope Eugenius III. It was not until Pope Paul IV that the Deanship and the Bishopric of Ostia were tied together, in his Bull of 22 August 1555, Cum venerabiles. Bullarum diplomatum et privilegiorum sanctorum Romanorum pontificum Taurensis editio (in Latin). Vol.Tomus sextus (6). Seb. Franco. 1860. pp.502–504.
According to the Passio S. Hippolyti, the first Maximus consecrated Pope Dionysius and was the first Bishop of Ostia to consecrate a pope, but the historical value of the document is in question: Lanzoni, p. 109: "Ma che questo privilegio, nel 259, fosse esercitato da un vescovo di nome Massimo non potrebbe affermarsi sicuramente su la fede della Passione di S. Ippolito, documento romanzesco e pieno di errori."
Maximus of Ostia was present at the Roman synod of October 313, conducted by Pope Miltiades. J. D. Mansi (ed.) Sacrorum Conciliorum nova et amplissima collectio editio novissima Tomus secundus (2) (Florence 1759), p. 437.
Bellator of Ostia subscribed to the decrees of the Roman Synod of February–March 499, held by Pope Symmachus. Mansi, Tomus Octavus (8), p. 235. Bishop Boniface of Velletri also subscribed, p. 233.
Bishop George was present at the Lateran council of 769: J. D. Mansi (ed.) Tomus duodecimus (12), p. 714. He was also present at a council in Mercia in 786: Dorothy Whitelock (2007 [1955]), English Historical Documents, c.500–1042, 2nd ed., p. 292.
Source for the period 996–1057: Otto Kares, Chronologie der Kardinalbischöfe im elften Jahrhundert, (in:) Festschrift zur Jahrhundertfeier des Gymnasiums am Burgplatz in Essen, Essen 1924, pp. 20, 23–25
Sources for the period 1057–1130: Hans-Walter Klewitz, Reformpapsttum und Kardinalkolleg, Darmstadt 1957; and Rudolf Hüls, Kardinäle, Klerus und Kirchen Roms: 1049–1130, Tübingen 1977. Both authorities indicate that the see of Velletri was united to Ostia in April 1060.[pageneeded]
Drogo was appointed by Pope Innocent II while he was in exile in Pisa in 1134. His predecessor's latest document was signed on 4 June 1133; his successor was signing documents on 9 April 1138. Ughelli, pp. 62–63. P. Jaffé, Regesta pontificum romanorum editio altera, ed. G. Loewenfeld (Leipzig:Veit 1885), p. 840. Barbara Zenker, Die Mitglieder des Kardinalcollegiums von 1130 bis 1159 (Würzburg 1964), pp. 13–15.
Pierre d'Estaing, Doctor of Canon Law, had been Bishop of Saint-Flour (1361–1368), and Bishop of Bourges (1368–1370). He was created a cardinal by Pope Urban V on 7 June 1370, and assigned the titular church of S. Maria in Trastevere. Eubel, I, p. 21, 139, 251.
Antonio Correr of Venice, the Bishop of Bologna (1407–1412), was created a cardinal by his uncle, Pope Gregory XII on 9 May 1408, and assigned the titular church of San Pietro in Vincoli. He was promoted Cardinal-bishop of Porto 1409–1431. Eubel, I, p. 31, 36, 37, 45, 141.
Fieschi had also been Cardinal-bishop of Albano 1518–1521, Sabina 1521–1523 and Porto 1523–1524.
Salvador Miranda, The Cardinals of the Holy Roman Church , Consistory of May 31, 1503
Giovanni Nanni Tedeschini-Piccolomini, Bishop of Siena (1503–1529), was created a cardinal by Pope Leo X on 1 April 1517, and assigned the titular church of Santa Sabina. In 1521 he was transferred to Santa Balbina. On 24 July 1524 he was promoted Cardinal-bishop of Albano (1524–1531); then on 22 September 1531 he was promoted to Palestrina (1531–1533); and then to Porto (1533–1535). Eubel, III, p. 15, 55–57, 297.
Gallio, Bishop of Manfredonia (1562–1573), who had been the private Secretary of the Pope, had been named a cardinal by Pope Pius IV in the Consistory of 12 March 1565, and was assigned the Deaconry of San Teodoro. He was promoted to San Pancrazio on 7 September 1565. He was then promoted Cardinal-bishop of Albano on 2 March 1587; then Bishop of Sabina (1589–1591) on 2 March 1589; Frascati 1591–1600; and Porto 1600–1603. Eubel, III, p. 40, 56, 58, 68, 76, 301. Gauchat, IV, p. 36.
A native of Florence, Deti, who was a nephew of Pope Clement VIII, was named a cardinal in the Consistory of 3 March 1599. He was first assigned the Deaconry of Sant'Adriano al Foro. He became Cardinal Priest of Santi Marcellino e Pietro al Laterano on 6 October 1614. He was promoted Cardinal-bishop of Albano (1623–1626) on 7 June 1623; of Frascati 1626; and of Porto 1626–1629. He became Bishop of Ostia on 20 August 1629. He died in Rome on 13 July 1630. Lorenzo Cardella (1793). Memorie storiche de' cardinali della santa Romana chiesa (in Italian). Vol.Tomo sesto (6). Roma: Pagliarini. pp.84–85. Gauchat, IV, p. 6 no. 34.
A Neapolitan noble, Carafa had also been Cardinal-bishop of Albano 1740–1751, and of Porto 1751–1753. Ritzler, V, p. 38 with notes 10–16. VI, pp. 39, 40, 48, 50.
A native of Naples, Spinelli was created a cardinal by Pope Clement XII on 17 January 1735, and assigned the titular church of Santa Pudenziana. He was promoted Cardinal-bishop of Palestrina on 9 April 1753, and advanced to Porto on 13 July 1759. He became Cardinal Bishop of Ostia and Dean of the College of Cardinals on 13 July 1761. He died 12 April 1763, and was buried in the Basilica of the Twelve Apostles in Rome. Ritzler, VI, pp. 7–8, with notes 51–53.
Cavalchini, a native of Milan, was created a cardinal by Pope Benedict XIII in his first Consistory for the creation of Cardinals on 9 September 1743, and assigned the titular church of Santa Maria della Pace. He was promoted Cardinal-bishop of Albano on 12 February 1759, and advanced to Ostia on 16 May 1763. Ritzler, VI, p. 31, with notes 12 and 13.
Serbelloni had been titular Archbishop of Patras in Greece, to qualify him for the post of Vice-Legate in Bologna. Serbelloni was created a cardinal by Pope Benedict XIV on 26 November 1753. He was Cardinal-bishop of Albano, 1763–1774. Ritzler, VI, p. 16, with notes 80 and 81.
Stuart was created a cardinal by Pope Benedict XIV on 3 July 1747, and assigned the titular church of Santa Maria in Porticu. He held a succession of other churches until, on 13 July 1761, he was promoted Cardinal-Bishop of Frascati, 1761–1803. He was promoted to Ostia on 26 September 1803. Ritzler, VI, p. 16 and notes 74–76.
Antonelli was created a Cardinal by Pope Pius VII on 24 April 1775, with the title of Santa Sabina. In 1794 he was appointed Cardinal-bishop of Palestrina (1794–1800), and Porto (1800–1807). He was Secretary of the Holy Office of the Universal and Roman Inquisition. He died on 23 January 1811. Annuario Pontificio 1779, p. 105. Annuario Pontificio 1801, pp. 5–6. Francesco Cancellieri (1825). Cenotaphium Leonardi Antonelli Cardinalis (in Italian and Latin). Pisaurum. pp.3–4. with notes. Ritzler, VI, p. 30.
Mattei was Archbishop of Ferrara (1777–1807 ). In the Conclave of 1799–1800 Cardinal Mattei had been one of the principal candidates, promoted by the Austrian interest led by Cardinal Franz Hrzan. Mattei was then named Cardinal-bishop of Palestrina (1800–1809) and Porto (1809–1814). Francis A. Burkle-Young (2000). Papal Elections in the Age of Transition, 1878–1922. Lanham MD USA: Lexington Books. pp.9–11. ISBN978-0-7391-0114-8. Ritzler, VI, p. 33, with notes 77-81; p. 215.
Somaglia was created a cardinal by Pope Pius VI on 1 June 1795, with the titulus of Santa Sabina. He was promoted Cardinal-bishop of Frascati 1814–1818, and then Porto (1818–1820). In 1818 he was appointed Vice-Chancellor of the Church. On 29 May 1820 he became Bishop of Ostia. Ritzler, VI, p. 38, with notes 90–96.
Pacca was also Cardinal-bishop of Frascati, 1818–1821; and of Porto, 1821–1830. Annuario Pontificio (Roma 1845), p. 87. Carlo Gazola (1844). In morte del cardinale Bartolomeo Pacca due prose (in Italian). Roma: Tip. delle Belle Arti.
Pignatelli di Belmonte was born in Naples. He was Prince of Belmonte, Duke of Acerenza, Marchese of Galatone and Count of Copertino. He was also Cardinal-bishop of Albano 1915–1948. Lentz, pp. 84–85.