The former Italian Catholic Diocese of Chiusi-Pienza, in Tuscany, existed until 1986. In that year it was united into the Diocese of Montepulciano-Chiusi-Pienza. The Diocese of Chiusi (Clusinus) was at first immediately subject to the Holy See, but was made a suffragan of archdiocese of Siena by Pope Pius II.Umberto Benigni (1908), "Chiusi-Pienza." The Catholic Encyclopedia Vol. 3 (New York: Robert Appleton Company, 1908); retrieved 11 December 2019. From 1459 to 1986, it was a suffragan of the archdiocese of Siena.

History Catacombs are found at Chiusi. The martyrdom of the deacon Irenaeus and the virgin Mustiola probably took place under Valerian. The monastery of San Salvatore in Amiata was traditionally said to have been built by Ratchis, King of the Lombards, in 747. The foundation document, however, is a forgery.Kehr III, p. 237: "Sed diplomata a Ratchis et ab Aistulfo, eius fratre, Erfoni primo Amiatino abbati concessa, omnino spuria esse nemo est quin dubitet." Afterwards the monastery rose to great power and influence.Cappelletti XVII, p. 574.

Bishop Francesco degli Atti (1348) was a doctor of Canon Law, noted for his De quarta canonica piorum legatorum debita episcopo, a treatise on the 25% of a bishop's income which ought to be spent on charity.

Chiusi formerly boasted of a relic, the purported betrothal ring of the Blessed Virgin, which was taken to Perugia about 1449 by an Augustinian friar; in consequence of this a war broke out between them, in which Perugia was victorious and remained in possession of the ring. Pope Sixtus IV confiscated the ring, and had it brought to the Vatican, but Clement VIII returned it to Perugia. Two hundred years later, a wedding ring of the Virgin was being shown in Semur in Burgundy; another is preserved at S. Maria in via Lata in Rome; and another at the abbey of Anchin near Douai in France.

Chapter and cathedral

The cathedral of Chiusi was dedicated to S. Secundinus.Riccardo Belcari (2007), "Il vescovo Florentinus e la cattedrale di San Secondiano a Chiusi," Hortus Artium Medievalium 13 (2007), pp. 25-38.

The cathedral was administered and served by a Chapter, originally composed of two dignities (the Provost and the Archpriest) and three Canons (canonici), along with four priests. The cathedral was a parish church, and the Archpriest and Provost were responsible for the parishioners' spiritual welfare.Ughelli III, p. 586. In 1620, there were the two dignities and eight Canons.Gauchat, p. 154, note 1. Later two dignities were added (the Archdeacon and the Prior), and there were nine Canons and twelve beneficiati.Coleti, addition to Ughelli III, p. 586.

In 1584, Bishop Masseo Bardi, O.F.M. (1581–1597) held a diocesan synod, and published the constitutions agreed upon at the meeting. Bishop Lucio Borghesi (1682–1705) presided over a diocesan synod in Chiusi in 1684, and had its constitutions published. He held another synod in 1688.J.-D. Mansi (ed.), Sacrorum Conciliorum nova et amplissima collectio, editio novissima, Tomus XXXVIter (Arnhem & Leipzig: H. Welter 1924), pp. 501, 523.

Losses of territory

In 1325, when the new diocese of Cortona was erected, Pope John XXII obtained part of the territory of the new diocese from the territory of the diocese of Chiusi.Cappelletti XVIII, p. 271.

On 22 April 1459, Pope Pius II issued the bull "Triumphans Pastor", in which he raised the diocese of Siena to metropolitan status, and assigned to it as suffragans the dioceses of Soano, Chiusi, Massa, and Grosseto.: "Necnon filias nostras praedictas Suanensem, Clusinensem et Grossetanensem et Massanensem Ecclesias, cum suis civitatibus et dioecesibus, iuribus el pertinentiis universis, Ecclesiae Seuensi et arcbiepiscopis praefatis, tamquam illorum metropolitanis et de eorum provincia...." On 13 August 1462, with the bull "Pro Excellenti", Pius II created a new diocese, the diocese of Pienza, with his native town as the seat of the bishop. Territory for the new diocese came in part from the diocese of Chiusi.Bullarum diplomatum et privilegiorum sanctorum romanorum pontificum V, pp. 166-169, at p. 167 §3: "ac arcem Tentinnam, cum Balneis Avinianis, Castilionis, Vallis Urciae, Campigliae, cum Balneis S. Philippi, Sancti Petri in campo Continiani, Perignani, Castri veteris, Montis Nigri, Sancti Angeli in colle, Castri Novi Abbatis, Seggiani, Ripae, Vinionis, Monticchielli et Fabricae, quae hactenus Clusinae dioecesis fuerunt, ab ipsa Clusina...."

In the papal bull "In supereminenti" of 25 September 1600, Pope Clement VIII created the new diocese of Città di Pieve in Tuscany. The territory for the new diocese was taken from the dioceses of Perugia, Orvieto, the Papacy itself, and Chiusi ("Laviani, Pusteoli, Gioelle et Panigarolae cum caeteris locis in universo marchionatu Clusii" and Santa Flora). Pieve was raised to the status of a city (civitas), and its collegiate church of Ss. Gervasius and Protasius was raised to the rank of a cathedral. Cappelletti, pp. 567-568. The bull mentions that Bishop Ludovico Martelli had recently died, which no doubt simplified the process envisioned by the Pope, since there would be no opposition or appeals from Chiusi. Pope Clement sent Magister Anselmo Dandini, his papal notary de numero participantium, who was also Referendary of the Two Signatures, as Commissary and Apostolic Visitor, to assess and arrange the divisions ("ad divisionem et assignationem fructuum, redituum et proventuum, ac bonorum huiusmodi procedens").Bullarum diplomatum X, p. 742, column 1. Pope Clement issued a second bull, "Super Universas", on 9 November 1601, in which he rehearsed all his orders from the first bull, ratified the arrangements made by Magister Dandini, and issued additional instructions for the organization of the diocese of Città di Pieve. In compensation for its losses, the episcopal revenues of Chiusi were to receive an annual payment of 1,000 scudi.Bullarum diplomatum X, pp. 740-750, especially §2 (pp. 741-742) for the annual payment. Chiusi finally received a new bishop, Fausto Mellari, on 22 April 1602.Gauchat, p. 154.

In the bull of 1 June 1772, preliminary to uniting the two dioceses of Chiusi and Pienza under one bishop, aeque personaliter, Pope Clement XIV removed four parishes from the diocese of Chiusi, Arcidorro, Monticello, Montelaterone and Casteldel Piano, transferring them to the diocese of Montalcino.Cappelletti XVII, p. 568. 624. On 15 June 1772, in the bull "Quemadmodum", Pope Clement united the dioceses of Chiusi and Pienza. Ritzler-Sefrin, Hierarchia catholica VI, p. 171, note 1.

Amalgamation On 15 June 1772, in the bull "Quemadmodum", Pope Clement united the dioceses of Chiusi and Pienza.

On 18 February 1984, the Vatican and the Italian State signed a new and revised concordat. Based on the revisions, a set of Normae was issued on 15 November 1984, which was accompanied in the next year, on 3 June 1985, by enabling legislation. According to the agreement, the practice of having one bishop govern two separate dioceses at the same time, aeque personaliter, was abolished. This applied to the diocese of Chiusi e Pienza. Instead, the Vatican continued consultations which had begun under Pope John XXIII for the merging of small dioceses, especially those with personnel and financial problems, into one combined diocese. On 30 September 1986, Pope John Paul II ordered that the dioceses of Montepulciano, Chiusi and Pienza be merged into one diocese with one bishop, with the Latin title Dioecesis Montis Politiani-Clusina-Pientina. The seat of the diocese was to be in Moontepulciano, and was to serve as the cathedral of the merged diocese. The cathedrals in Chiusi and Pienza were to become co-cathedrals, and the cathedral Chapters were each to be a Capitulum Concathedralis. There was to be only one diocesan Tribunal, in Montepulciano, and likewise one seminary, one College of Consultors, and one Priests' Council. The territory of the new diocese was to include the territory of the former dioceses of Chiusi and Pienza, and was suffragan to the archdiocese of Siena.Acta Apostolicae Sedis 79 (Città del Vaticano 1987), pp. 750-752.

Bishops of Chiusi

to 1200

... Lucius Petronius Dexter (d. 322)Petronius: Corpus Inscriptionum Latinarum, Vol. X, fasc. 1, no. 2548. Lanzoni, p. 553, no. 1. ... [Florentius (465)]Florentius is among the bishops present at the Roman synod of Pope Hilarius in 465. But he was Bishop of Telesia (Telesinus, not Clusinus). J.-D. Mansi (ed.), Sacrorum Conciliorum nova et amplissima collectio, editio novissima, Tomus VII (Florence: A. Zatta 1762), pp. 967-968. Ughelli III, p. 587. Lanzoni, p. 554. ... Florentinus (attested 558–560)Lanzoni, p. 554, no. 2. A letter of Pelagius is addressed to Florentino episcopo, who is identified as a bishop of Chiusi on the basis of an inscription, C.I.L. X, 1, no. 2587. ... Ecclesius (attested 600, 604)Bishop Ecclesius is known from three letters of Pope Gregory I (Registrum X. 13; XI.3; XIV.15). Ughelli III, p. 587, erroneously calls him Eulogius. Lanzoni, p. 554, no. 3. ... Marcellinus (attested 649)Bishop Marcellinus was present at the Lateran council of Pope Martin I on 3 October 649. J.-D. Mansi (ed.), Sacrorum Conciliorum nova et amplissima collectio, editio novissima, Tomus X (Florence: A. Zatta 1764), p. 866. Ughelli, p. 587. ... Theodorus (attested 676, 680)Bishop Theodorus took part in the Roman synod of Pope Agatho in 680. Ughelli, p. 587. Mansi, Tomus XI (Florence: A. Zatta 1765), p. 775. Cappelletti XVII, p. 577. ... Arcadius (attested 729–743) Gisolfus (attested 752)Bishop Gisolfus is mentioned in the bull "Convenit Apostolico" of Pope Stephen II of 20 May 752. Cappelletti XVII, pp. 400, 579. ... Andreas (attested 826)Bishop Andreas attended the Roman synod of Pope Eugenius II on 15 November 826. J.-D. Mansi (ed.), Sacrorum Conciliorum nova et amplissima collectio, editio novissima, Tomus XIV (Venice: A. Zatta 1769), p. 1000. Ughelli III, p. 592. Theobaldus (attested 835, 845)Bishop Theobaldus wrote a treatise on predestination, dedicated to Bishop Nothingus of Brescia (844–865). Ughelli, pp. 592-616. Cappelletti, p. 579. Taceprandus (c. 850, 853)Taceprandus: Cappelletti, p. 579. Liutprandus (attested 861)Bishop Liutprandus was present at the Roman council of Pope Nicholas I in 861. J.-D. Mansi (ed.), Sacrorum Conciliorum nova et amplissima collectio, editio novissima, Tomus XV (Venice: A. Zatta 1770), p. 603. Ughelli, p. 616. Cappelletti, p. 579. ... Christianus (attested 911) ... Liutto (attested 967, 968)Bishop Liutto (Liuto, Lyudo) was present at the synod of Ravenna on 25 April 967. J.-D. Mansi (ed.), Sacrorum Conciliorum nova et amplissima collectio, editio novissima, Tomus XVIII (Venice: A. Zatta 1773), p. 500. On 2 January 968, he subscribed a bull for Pope John XIII. Schwartz, p. 203. ... Arialdus (attested 998–1007, 1021 or later)Pope Benedict VIII (1012–1021) sent a letter to Bishop Arialdus, instructing him to consecrate the abbey of S. Salvatore in Monte Amiato. Kehr III, p. 232, no. 4. Schwartz, p. 203. ... Wido (Guido) (attested 1027–1038)Bishop Wido was present at the Roman synod of Pope John XIX of 6 April 1027. Schwartz, pp. 203-204. ... Petrus (attested 1049)Bishop Petrus attended the Roman synod of Pope Leo IX of 22 April 1049. Ughelli, pp. 626-630. Schwartz, p. 204. Wido (attested 1055) Petrus (attested 1058) Joannes (attested 1059) Lanfranc (attested 1065–1098) ... Petrus (attested 1112–1127) ... Martinus (attested 1146–1147)Martinus: Ughelli III, pp. 632-633. ... Ubertus (attested 1159) ... Rainerius (attested 1176)Ughelli, p. 633. Leo (attested 1179)Bishop Leo was present at the Third Lateran Council of Pope Alexander III in March 1179. J.-D. Mansi (ed.) Sacrorum Conciliorum nova et amplissima collectio, editio novissima, Tomus XXII (Venice: A. Zatta 1778), p. 459. Ughelli, p. 633. Theobaldus (attested 1191–1196)Theobaldus: Ughelli, p. 633. Kehr III, p. 234, nos. 15-17. ...

1200 to 1500