| Date | From | To | ||
|---|---|---|---|---|
| 12th Century | Diocese of Barbastro, Spain | Erected | ||
| 12th Century | Diocese of Braga, Portugal | Elevated | Archdiocese of Braga, Portugal | Elevated |
| 12th Century | Diocese of Caserta, Italy | Erected | ||
| 12th Century | Diocese of Hvar, Croatia | Erected | ||
| 12th Century | Diocese of Ischia, Italy | Erected | ||
| 12th Century | Diocese of Lamego, Portugal | Erected | ||
| 12th Century | Diocese of Messina, Italy | Elevated | Archdiocese of Messina, Italy | Elevated |
| 12th Century | Diocese of Molfetta, Italy | Erected | ||
| 12th Century | Diocese of Galtelli, Italy | Erected | ||
| 12th Century | Diocese of Osma, Spain | Erected | ||
| 12th Century | Diocese of Patti, Italy | Erected | ||
| 12th Century | Diocese of Bisaccia, Italy | Erected | ||
| 12th Century | Diocese of Sant'Angelo dei Lombardi, Italy | Erected | ||
| 12th Century | Diocese of Ampurias, Italy | Erected | ||
| 12th Century | Diocese of Capaccio, Italy | Erected | ||
| 12th Century | Territorial Abbey of Montevergine, Italy | Erected | ||
| 12th Century | Diocese of Terralba, Italy | Erected | ||
| 12th Century | Diocese of Tuscanella, Italy
Diocese of Viterbo, Italy | United | Diocese of Viterbo e Tuscania, Italy | United |
| 12th Century | Apostolic Penitentiary, Roman Curia | Erected | ||
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