[1] The diocese of Capaccio (Caputaquensis), as it had grown over the centuries, had become extremely large in geographical extent, and, as the population grew as well, it became much more difficult to administer.

[3] Discussions on dividing the diocese had already begun in the reign of Pope Gregory XVI,[4] division of assets and relocation of facilities being of prime consideration.

[6] On 21 September 1850, at the request of Archbishop Marino Paglia of Salerno and of king Ferdinand II of the Two Sicilies,[7] in the bull entitled "Ex quo imperscrutabili", Pope Pius IX established the Diocese of Diano.

[11] The first bishop of Diano, Valentino Vignone, was nominated by the king on 16 November 1850, and confirmed by Pope Pius IX on 17 February 1851.

The Second Vatican Council (1962–1965), in order to ensure that all Catholics received proper spiritual attention, decreed the reorganization of the diocesan structure of Italy and the consolidation of small and struggling dioceses.

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.

There was to be only one diocesan Tribunal, in Teggiano, and likewise one seminary, one College of Consultors, and one Priests' Council.