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 Montepulciano, 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.[1]
