The natural borders of the diocese are the Tyrrhenian Belt which goes from Oliveri to Tusa, for a length of about 102 kilometres, and the Nebrodi mountain range.

[3] Four of its bishops are known by name: There was also a predecessor in the form of a Diocese of Lipari, which appears to have become extinct, perhaps due to Saracen raids in the 9th century.

Frederick III of Sicily (1295–1337) devastated Patti because the town was a supporter of his Angevin rivals, Robert and Philip of Naples.

[12] The French Pope John XXII, who supported the Angevins, laid all of Sicily under an interdict, which lasted from 1321 to 1335, causing severe problems between the Sicilian episcopate and the monarchy.

The diocese had in the early 20th century 49 parishes, 20,000 inhabitants, 5 religious houses of men, and 15 of sisters, conducting 4 institutes for girls and several schools.