Changes in Ecclesiastical Jurisdictions (3ʳᵈ century)

Date	Country	Change
220	France	Diocese of Arles was established
237	Italy	Diocese of Fondi was established
250	Algeria	Diocese of Cirta was established
250	Algeria	Diocese of Hippo Regius was established
250	Austria	Metropolitan Archdiocese of Lauriacum was established
250	Austria	Metropolitan Archdiocese of Tiburnia was established
250	France	Diocese of Paris was established
250	France	Diocese of Tours was established
250	Germany	Diocese of Trier was established
250	Italy	Diocese of Trani was established
250	Spain	Diocese of Emerita Augusta was established
250	Spain	Diocese of Iliturgi was suppressed (to establish Diocese of Tucci)
250	Spain	Diocese of León was established
250	Spain	Diocese of Sevilla was established
250	Spain	Diocese of Tarragona was established
250	Spain	Diocese of Tucci was established (from the suppressed Diocese of Iliturgi)
250	Spain	Diocese of Zaragoza was established
250	Tunisia	Diocese of Tambeæ was established
250	Tunisia	Diocese of Ululi was established
250	Turkiye	Diocese of Ægeæ was established
259	Italy	Diocese of Lentini was established
260	France	Diocese of Cimiez was established
280	Iraq	Diocese of Perat-Maishan (Chaldean Rite) was established
280	Italy	Diocese of Fossombrone was established
280	Spain	Diocese of Málaga was established
294	Lebanon, Turkiye	Diocese of Cilicia (Armenian Rite) was established
300	Albania	Diocese of Amantia was established
300	Algeria	Diocese of Calama was established
300	Algeria	Diocese of Thagaste was established
300	Austria	Diocese of Virunum was established
300	Croatia	Diocese of Poreč was established
300	Croatia	Diocese of Ragusa was established
300	Croatia	Diocese of Salona was established
300	Croatia	Diocese of Sisak was established
300	Croatia	Diocese of Vinkovci was established
300	Cyprus	Diocese of Amathus was established
300	Cyprus	Diocese of Soli was established
300	Egypt	Diocese of Nitria was established
300	Egypt	Diocese of Rhinocolura was established
300	France	Diocese of Ajaccio was established
300	France	Diocese of Alba Helvianorum was established
300	France	Diocese of Albi was established
300	France	Diocese of Amiens was established
300	France	Diocese of Angoulême was established (became suffragan of Bordeaux)
300	France	Diocese of Apt was established
300	France	Diocese of Auvergne was established
300	France	Diocese of Auxerre was established (became suffragan of Sens)
300	France	Diocese of Beauvais was established
300	France	Metropolitan Archdiocese of Bordeaux was established (with suffragan sees Angoulême and Périgueux)
300	France	Diocese of Cahors was established
300	France	Diocese of Chartres was established (became suffragan of Sens)
300	France	Diocese of Châlon-sur-Saône was established (became suffragan of Lyon)
300	France	Diocese of Die was established
300	France	Metropolitan Archdiocese of Eauze was established
300	France	Diocese of Javols was established
300	France	Diocese of Langres was established (became suffragan of Lyon)
300	France	Diocese of Le Puy-en-Velay was established
300	France	Diocese of Lyon was promoted as Metropolitan Archdiocese of Lyon (with suffragan sees Autun, Châlon-sur-Saône and Langres)
300	France	Diocese of Marseille was established
300	France	Diocese of Metz was established
300	France	Diocese of Narbonne was established
300	France	Diocese of Orange was established
300	France	Diocese of Orléans was established (became suffragan of Sens)
300	France	Diocese of Poitiers was established
300	France	Diocese of Périgueux was established (became suffragan of Bordeaux)
300	France	Diocese of Reims was established
300	France	Diocese of Rennes was established
300	France	Diocese of Rouen was established
300	France	Metropolitan Archdiocese of Sens was established (with suffragan sees Auxerre, Chartres, Orléans, Paris and Troyes)
300	France	Diocese of Soissons was established
300	France	Diocese of Strasbourg was established
300	France	Diocese of Toulouse was established
300	France	Diocese of Troyes was established (became suffragan of Sens)
300	France	Diocese of Vaison was established
300	France	Diocese of Vienne was established
300	France	Diocese of Évreux was established
300	Germany	Diocese of Köln was established
300	Greece	Diocese of Corfù was established
300	Greece	Diocese of Eurœa was established
300	Greece	Metropolitan Archdiocese of Larissa was established
300	Greece	Diocese of Megara was established
300	Greece	Metropolitan Archdiocese of Mytilene was established
300	Greece	Diocese of Philippi was promoted as Metropolitan Archdiocese of Philippi
300	Greece	Diocese of Scyrus was established
300	Iraq	Archdiocese of Kaškar (Chaldean Rite) was established
300	Iraq	Diocese of Seleucia–Ctesifonte (Chaldean Rite) was established
300	Italy	Diocese of Amiterno was established
300	Italy	Diocese of Ancona was established
300	Italy	Diocese of Arezzo was established
300	Italy	Diocese of Assisi was established (without ecclesiastical province)
300	Italy	Diocese of Asti was established
300	Italy	Diocese of Bologna was established
300	Italy	Diocese of Cagliari was established
300	Italy	Diocese of Calvi was established
300	Italy	Diocese of Carini was established
300	Italy	Diocese of Chiusi was established (became suffragan of Roma)
300	Italy	Diocese of Civitavecchia was established (without ecclesiastical province)
300	Italy	Diocese of Claterna was established
300	Italy	Diocese of Eca was established
300	Italy	Diocese of Eclena was established
300	Italy	Diocese of Erdonia was established
300	Italy	Diocese of Faenza was established
300	Italy	Diocese of Fermo was established
300	Italy	Diocese of Firenze was established
300	Italy	Diocese of Forlimpopoli was established
300	Italy	Diocese of Formia was established
300	Italy	Diocese of Forum Clodii was established
300	Italy	Diocese of Genova was established
300	Italy	Diocese of Labico was established
300	Italy	Diocese of Lucca was established (without ecclesiastical province)
300	Italy	Diocese of Modena was established
300	Italy	Diocese of Nuceria was established
300	Italy	Diocese of Padova was established
300	Italy	Diocese of Palestrina was established (became suffragan of Roma)
300	Italy	Diocese of Parma was established
300	Italy	Diocese of Pesaro was established (without ecclesiastical province)
300	Italy	Diocese of Pisa was established
300	Italy	Diocese of Pistoia was established
300	Italy	Diocese of Pitinum was established
300	Italy	Diocese of Porto was established (became suffragan of Roma)
300	Italy	Diocese of Ravenna was established
300	Italy	Diocese of Rimini was established (without ecclesiastical province)
300	Italy	Diocese of Septempeda was established
300	Italy	Diocese of Siena was established (became suffragan of Roma)
300	Italy	Diocese of Siracusa was established
300	Italy	Diocese of Sora was established
300	Italy	Diocese of Teano was established
300	Italy	Diocese of Terracina was established (without ecclesiastical province)
300	Italy	Diocese of Torres was established
300	Italy	Diocese of Tre Taverne was established
300	Italy	Diocese of Vercelli was established
300	Italy	Diocese of Verona was established
300	Jordan	Metropolitan Archdiocese of Petra was established
300	Lebanon	Archdiocese of Heliopolis was established
300	Palestine	Metropolitan Archdiocese of Scythopolis was established
300	Portugal	Diocese of Elbora was established
300	Portugal	Diocese of Salácia was established
300	Romania	Archdiocese of Constantia antea Tomi was established
300	Serbia	Diocese of Horreomargum was established
300	Serbia	Archdiocese of Iustiniana prima was established
300	Serbia	Diocese of Naissus was established
300	Serbia	Diocese of Remesiana was established
300	Serbia	Diocese of Singidinum was established
300	Serbia	Diocese of Srijem was established
300	Serbia	Metropolitan Archdiocese of Viminacium was established
300	Slovenia	Diocese of Ptuj was established
300	Spain	Diocese of Auca was established
300	Spain	Diocese of Basti was established
300	Spain	Diocese of Córdoba was established
300	Spain	Diocese of Egabro was established
300	Spain	Diocese of Elvira was established
300	Spain	Diocese of Palencia was established
300	Spain	Diocese of Urci was established
300	Syria	Diocese of Arethusus was established
300	Syria	Metropolitan Archdiocese of Berœa was established
300	Syria	Diocese of Circesium was established
300	Syria	Metropolitan Archdiocese of Damascus (Greek-Melkite Rite) was established
300	Syria	Metropolitan Archdiocese of Hemesa was established
300	Syria	Diocese of Philippopolis was established
300	Tunisia	Diocese of Bennefa was established
300	Tunisia	Diocese of Buslacena was suppressed
300	Tunisia	Diocese of Thibiuca was established
300	Turkiye	Metropolitan Archdiocese of Amida was established
300	Turkiye	Metropolitan Archdiocese of Ancyra was established
300	Turkiye	Diocese of Apollonias was established
300	Turkiye	Diocese of Batnæ was established
300	Turkiye	Diocese of Charræ was established
300	Turkiye	Archdiocese of Colonia was established
300	Turkiye	Diocese of Colossæ was promoted as Archdiocese of Colossæ
300	Turkiye	Diocese of Eumenia was established
300	Turkiye	Metropolitan Archdiocese of Gangra was established
300	Turkiye	Diocese of Lampsacus was established
300	Turkiye	Diocese of Laodicea was promoted as Metropolitan Archdiocese of Laodicea
300	Turkiye	Archdiocese of Martiropolis was established
300	Turkiye	Archdiocese of Nazianzus was established
300	Turkiye	Diocese of Nicomedia was promoted as Metropolitan Archdiocese of Nicomedia
300	Turkiye	Metropolitan Archdiocese of Nicæa was established
300	Turkiye	Archdiocese of Nisibis was established
300	Turkiye	Diocese of Nyssa was established
300	Turkiye	Archdiocese of Parium was established
300	Turkiye	Diocese of Prusa was established
300	Turkiye	Diocese of Samosata was established
300	Turkiye	Diocese of Sasima was established
300	Turkiye	Metropolitan Archdiocese of Sebastia was established
300	Turkiye	Diocese of Sebastopolis was established
300	Turkiye	Diocese of Sebastopolis in Thracia was established
300	Turkiye	Metropolitan Archdiocese of Synnadæ was established
300	Turkiye	Diocese of Troas was established

Changes in Ecclesiastical Jurisdictions

in 3ʳᵈ century