Diocese in the province of Avellino, Italy, suffragan of Salerno, dates from the eleventh century. Among its bishops were

• Guido (1004);
• St. Amatus (1167), author of a history of the Normans in Apulia and Calabria;
• Roger (1198), who restored the cathedral;
• Cardinal Pietro Paolo Parisio (1538), who presided at the Council of Trent;
• Francesco Arcudio (1639), a Theatine;
• Fulgenzio Arminio Monforte (1669), an Augustinian.

In 1820 Montemartino was united to Nusco. St. John, a Benedictine (1084) was the first Bishop of Montemartino; forty of his successors are known. Nusco has 19 parishes, with 38,300 inhabitants, and 4 religious houses.