At the Lateran Palace, on 14 January 1121, Pope Calixtus signed the bull "Et synodalium", the text of which is found only in the Cronica Trium Tabernarum.

He did this after having received an embassy from Count Gaufredus of Catanzaro and the people of Tres Taberna, requesting restoration of the diocese, and after sending Cardinal Desiderius of S. Prassede to Calabria on an inspection tour.

In July 1121 Pope Calixtus travelled to Campania, spending time in Aversa, Salerno, Melfi, and Taranto.

[9] In 1122, Pope Calixtus II transferred to Catanzaro the see of Taverna (Tres Tabernae), which is taken as the date of foundation of the diocese, at least according to the Catholic Encyclopedia.

[11] No bishop of Calabria attended the First Lateran Council of Pope Calixtus II in Rome in 1123, held to deal with investiture, simony, clerical concubinage, and an expedition against the Saracens.

By the end of the century, the Liber censuum indicates that it had become a suffragan (subordinate) of the archdiocese of Reggio Calabria, as the diocese of Catanzaro (Catacensis).

[14] In the earthquake of 8 March 1832, the most severely damaged buildings were: the school (lyceum), the headquarters of the royal intendent, the civic hospital, and the prison.

On 5 July 1927, [Pope Pius XI] changed the status of Catanzaro, liberating it from the metropolitan jurisdiction of Reggio Calabria and making it directly dependent on the Holy See (Papacy).

[21] On 18 February 1984, the Vatican and the Italian State signed a new and revised concordat, which was accompanied in the next year by enabling legislation.