Date | Country | Change |
| 1101 |  Spain | Diocese of Barbastro–Roda was established (from the suppressed Diocese of Roda) |
| 1101 | Spain | Diocese of Roda was suppressed (to establish Diocese of Barbastro–Roda) |
| 1101.08.07 |  Italy | Metropolitan Archdiocese of Bari was renamed as Metropolitan Archdiocese of Bari e Canosa |
| 1101.08.07 | Italy | Diocese of Canosa was demoted as Archpresbyterate nullius of Canosa |
| 1102 | Spain | Diocese of Salamanca was restored (from former Diocese of Caliábria) |
| 1102.04.18 |  England | Diocese of Chester was suppressed (to establish Diocese of Coventry) |
| 1102.04.18 | England | Diocese of Coventry was established (from the suppressed Diocese of Chester) |
| 1104 |  Sweden | Diocese of Lund was promoted as Metropolitan Archdiocese of Lund (with suffragan sees Århus, Børglum, Linköping, Nidaros, Odense, Oslo, Ribe, Roskilde, Schleswig, Skálholt, Skara, Uppsala, Västerås and Viborg) |
| 1106 |  Iceland | Diocese of Hólar was established (from Diocese of Skálholt and became suffragan of Lund) |
| 1106 | Italy | Diocese of Chioggia was established (from the suppressed Diocese of Malamocco and became suffragan of Grado) |
| 1106 | Italy | Diocese of Malamocco was suppressed (to establish Diocese of Chioggia) |
| 1107.06.20 |  Scotland | Diocese of Dunkeld was established |
| 1109 | England | Diocese of Ely was established (from Diocese of Lincoln) |
| 1109 |  Palestine | Diocese of Bethlehem–Ascalon was established |
| 1110 | Italy | Diocese of Anglona was established (from the suppressed Diocese of Tursi and became suffragan of Acerenza) |
| 1110 | Italy | Diocese of Ottana was established (became suffragan of Torres) |
| 1110 | Italy | Archpresbyterate nullius of Santa Maria Assunta di Carpi was established (from Diocese of Reggio Emilia) |
| 1110 | Italy | Diocese of Tursi was suppressed (to establish Diocese of Anglona) |
| 1110.01.25 | Spain | Diocese of Segovia was restored |
| 1111 |  Ireland | Abbacy nullius of Achonry was suppressed (to Diocese of Killala) |
| 1111 | Ireland | Abbacy nullius of Aghaboe was promoted as Diocese of Aghaboe |
| 1111 | Ireland | Abbacy nullius of Aghadoe was suppressed (to Diocese of Raigh Maighe Beiscirt) |
| 1111 | Ireland | Abbacy nullius of Ardcarne was suppressed (to Diocese of Elphin) |
| 1111 | Ireland,  Northern Ireland | Abbacy nullius of Clogher was promoted as Diocese of Clogher |
| 1111 | Ireland | Abbacy nullius of Clonfert was promoted as Diocese of Clonfert |
| 1111 | Ireland | Abbacy nullius of Cloyne was promoted as Diocese of Cloyne |
| 1111 | Ireland | Abbacy nullius of Cong was promoted as Diocese of Cong |
| 1111 | Ireland | Abbacy nullius of Cork was promoted as Diocese of Cork |
| 1111 | Ireland | Abbacy nullius of Dunshaughlin was suppressed (to Abbacy nullius of Clonard) |
| 1111 | Ireland | Abbacy nullius of Elphin was promoted as Diocese of Elphin (gained territory from the suppressed Abbacy nullius of Ardcarne) |
| 1111 | Ireland | Abbacy nullius of Ferns was promoted as Diocese of Ferns |
| 1111 | Ireland | Abbacy nullius of Glenndálocha was promoted as Diocese of Glendalough |
| 1111 | Ireland | Abbacy nullius of Kildare was promoted as Diocese of Kildare |
| 1111 | Ireland | Abbacy nullius of Killala was promoted as Diocese of Killala (gained territory from the suppressed Abbacy nullius of Achonry) |
| 1111 | Ireland | Abbacy nullius of Killaloe was promoted as Diocese of Killaloe |
| 1111 | Ireland | Abbacy nullius of Leighlin was promoted as Diocese of Leighlin |
| 1111 | Ireland | Abbacy nullius of Lismore was promoted as Diocese of Lismore |
| 1111 | Ireland | Abbacy nullius of Ardfert was promoted as Diocese of Raigh Maighe Beiscirt (gained territory from the suppressed Abbacy nullius of Aghadoe) |
| 1111 | Ireland | Abbacy nullius of Tuam was promoted as Diocese of Tuam |
| 1111 |  Lebanon | Diocese of Beirut was established |
| 1111 | Northern Ireland | Abbacy nullius of Ardstraw was promoted as Diocese of Ardstraw |
| 1113 | Italy | Diocese of Caserta was established (from Metropolitan Archdiocese of Capua, from the suppressed Diocese of Galazia in Campania and became suffragan of Napoli) |
| 1113 | Italy | Diocese of Gallura was renamed as Diocese of Civita |
| 1113 | Italy | Diocese of Galazia in Campania was suppressed (to establish Diocese of Caserta) |
| 1113 |  Portugal | Diocese of Porto was restored (from Metropolitan Archdiocese of Braga and without ecclesiastical province) |
| 1114 | Italy | Provostry nullius of Borgo San Donnino was established (from Diocese of Parma and Diocese of Piacenza) |
| 1114 | Italy | Diocese of Isola was established |
| 1114 | Portugal | Diocese of Dume was suppressed (to Diocese of San Martiño de Mondoñedo–Dume) |
| 1114 | Scotland | Diocese of Glasgow was restored |
| 1114 | Spain | Diocese of San Martiño de Mondoñedo was renamed as Diocese of San Martiño de Mondoñedo–Dume (gained territory from the suppressed Diocese of Dume) |
| 1116 | Spain | Diocese of Barbastro–Roda lost territory to Diocese of Huesca–Jaca |
| 1117 | Ireland | Diocese of Raigh Maighe Beiscirt was renamed as Diocese of Ardfert and Aghadoe |
| 1117 | Spain | Diocese of Besalú was established (from Diocese of Gerona and Diocese of Vic) |
| 1118 | Ireland | Diocese of Elphin was renamed as Diocese of Roscommon |
| 1118 | Spain | Diocese of Tarazona was restored (became suffragan of Tarragona) |
| 1119 | Italy | Diocese of Porto was renamed as Diocese of Porto e Santa Rufina (gained territory from the suppressed Diocese of Santa Rufina) |
| 1119 | Italy | Diocese of Santa Rufina was suppressed (to Diocese of Porto e Santa Rufina) |
| 1120 |  Croatia | Diocese of Ragusa was promoted as Metropolitan Archdiocese of Ragusa (with suffragan see Bosnia) |
| 1120 | Ireland | Diocese of Aghaboe was renamed as Diocese of Ossory |
| 1120 | Italy | Diocese of Galtellì was established (from Diocese of Civita) |
| 1120 | Italy | Diocese of Labico was suppressed (to establish Diocese of Tusculum) |
| 1120 | Italy | Diocese of Tusculum was established (from the suppressed Diocese of Labico and became suffragan of Roma) |
| 1120 | Spain | Diocese of Besalú was suppressed (to Diocese of Gerona and Diocese of Vic) |
| 1120.02.27 | Spain | Diocese of Santiago de Compostela was promoted as Metropolitan Archdiocese of Santiago de Compostela (with suffragan sees Ávila, Lugo, Ourense, Salamanca, San Martiño de Mondoñedo–Dume, Segovia and Tui) |
| 1121 | Italy | Diocese of Catanzaro was established (from Diocese of Squillace) |
| 1121 | Spain | Diocese of Sigüenza was restored (became suffragan of Toledo) |
| 1121 | Spain | Diocese of Zamora was restored (from Diocese of Astorga and became suffragan of Braga) |
| 1122 | Lebanon | Metropolitan Archdiocese of Tyrus was established |
| 1123 | Italy | Diocese of Montepeloso was restored (from Diocese of Tricarico and became suffragan of Acerenza) |
| 1125 |  Germany | Diocese of Lebus was established (became suffragan of Gniezno) |
| 1125 |  Norway | Diocese of Stavanger was established (from Diocese of Bjørgvin) |
| 1125 | Scotland | Diocese of Aberdeen was established (from the suppressed Diocese of Mortlach) |
| 1125 | Scotland | Diocese of Mortlach was suppressed (to establish Diocese of Aberdeen) |
| 1126 | Croatia | Diocese of Alba maritima was suppressed (to establish Diocese of Skradin) |
| 1126 | Croatia | Diocese of Skradin was established (from the suppressed Diocese of Alba maritima) |
| 1126 |  Greenland | Diocese of Gardar was established |
| 1126.05 | Italy | Territorial Abbacy of Montevergine was established (from Diocese of Avellino and became suffragan of Benevento) |
| 1128 | Scotland | Diocese of Whithorn was restored |
| 1129 | Sweden | Diocese of Strängnäs was established (became suffragan of Lund) |
| 1130 | Italy | Diocese of Terralba was established |
| 1131 |  Austria | Metropolitan Archdiocese of Salzburg lost territory to Diocese of Gurk |
| 1131.09.04 | Italy | Diocese of Cefalù was restored (from Diocese of Agrigento) |
| 1133 | Italy | Diocese of Montepeloso was suppressed (to Diocese of Andria) |
| 1133 | Spain | Diocese of Huesca–Jaca lost territory to Diocese of Barbastro–Roda |
| 1133.03.19 | Italy | Diocese of Genova was promoted as Metropolitan Archdiocese of Genova (with suffragan sees Accia, Bobbio, Mariana and Nebbio) |
| 1133.04.11 | England | Diocese of Carlisle was established (from Diocese of Durham and became suffragan of York) |
| 1133.05.27 | Italy | Diocese of Brugnato was established (from Metropolitan Archdiocese of Genova and Diocese of Luni and became suffragan of Genova) |
| 1134 |  Isle of Man | Diocese of Man was suppressed (to establish Diocese of Sodor) |
| 1134 | Scotland | Diocese of Sodor was established (from Diocese of Nidaros and from the suppressed Diocese of Man) |
| 1135 |  Hungary | Diocese of Kalocsa was promoted as Metropolitan Archdiocese of Kalocsa (with suffragan sees Csanád, Oradea Mare, Pécs and Transilvania) |
| 1137 | Scotland | Diocese of Birsay was renamed as Diocese of Kirkwall |
| 1138.04.09 | Italy | Diocese of Grosseto was established (from the suppressed Diocese of Roselle and became suffragan of Roma) |
| 1138.04.09 | Italy | Diocese of Roselle was suppressed (to establish Diocese of Grosseto) |
| 1139 | Spain | Diocese of Astorga lost territory to Metropolitan Archdiocese of Braga |
| 1140 | Italy | Diocese of Atina was demoted as Provostry nullius of Atina (lost territory to Diocese of Sora and without ecclesiastical province) |
| 1140 | Italy | Abbacy nullius of Santi Vincenzo ed Anastasio alle Tre Fontane was established |
| 1140 |  Poland | Diocese of Wollin was established (became suffragan of Gniezno) |
| 1143 | Spain | Diocese of Coria was restored (became suffragan of Santiago de Compostela) |
| 1144 | Croatia | Diocese of Hvar was established (from Metropolitan Archdiocese of Split) |
| 1144 | Italy | Abbacy nullius of Fontevivo was established (from Diocese of Parma) |
| 1144 | Italy | Abbacy nullius of Santa Maria di Polsi was established |
| 1145 | Spain | Diocese of Barbastro–Roda lost territory to Diocese of Huesca–Jaca |
| 1145 | Spain | Metropolitan Archdiocese of Sevilla was suppressed |
| 1145 | Spain | Diocese of Urci was restored |
| 1146 |  France | Diocese of Aleth was suppressed (to establish Diocese of Saint-Malo) |
| 1146 | France | Diocese of Saint-Malo was established (from the suppressed Diocese of Aleth and became suffragan of Tours) |
| 1146 | Scotland | Diocese of Caithness was established |
| 1146 | Spain | Diocese of Asidonia was suppressed |
| 1147 | Portugal | Diocese of Lisboa was restored |
| 1148 | Poland | Diocese of Kujawy–Pomorze was renamed as Diocese of Kujawy–Pomorze |
| 1149 | Spain | Diocese of Barbastro–Roda was suppressed (to Diocese of Huesca–Jaca and to establish Diocese of Lérida) |
| 1149 | Spain | Diocese of Lérida was restored (from the suppressed Diocese of Barbastro–Roda and became suffragan of Tarragona) |
| 1150 | Italy | Diocese of Ostia was renamed as Diocese of Ostia–Velletri (gained territory from the suppressed Diocese of Velletri) |
| 1150 | Italy | Diocese of Velletri was suppressed (to Diocese of Ostia–Velletri) |
| 1150 | Scotland | Diocese of Brechin was established (gained territory from Diocese of Dunkeld) |
| 1150 | Scotland | Diocese of Dunblane was established (from Diocese of Dunkeld) |
| 1150 | Scotland | Diocese of Dunkeld lost territory to Diocese of Brechin |
| 1150 | Spain | Diocese of Elvira was suppressed |
| 1151 | Spain | Diocese of Tortosa was restored (became suffragan of Tarragona) |
| 1152 | Ireland | Diocese of Achonry was restored (from Diocese of Killala and became suffragan of Tuam) |
| 1152 | Ireland | Abbacy nullius of Annaghdown was promoted as Diocese of Annaghdown (became suffragan of Tuam) |
| 1152 | Ireland | Abbacy nullius of Ardagh was promoted as Diocese of Ardagh (became suffragan of Armagh) |
| 1152 | Ireland | Diocese of Ardfert and Aghadoe lost territory to Diocese of Inniscathy |
| 1152 | Ireland | Abbacy nullius of Ardmore was promoted as Diocese of Ardmore (became suffragan of Cashel) |
| 1152 | Ireland, Northern Ireland | Abbacy nullius of Brefinnia was promoted as Diocese of Brefinnia (became suffragan of Armagh) |
| 1152 | Ireland | Diocese of Cashel was promoted as Metropolitan Archdiocese of Cashel (with suffragan sees Ardfert and Aghadoe, Ardmore, Cloyne, Cork, Emly, Glendalough, Inniscathy, Kilfenora, Killaloe, Leighlin, Limerick, Lismore, Roscrea and Waterford) |
| 1152 | Ireland | Abbacy nullius of Ceanannus Mór was promoted as Diocese of Ceanannus Mór (became suffragan of Armagh) |
| 1152 | Ireland | Abbacy nullius of Clonard was promoted as Diocese of Clonard (gained territory from the suppressed Abbacy nullius of Trim and became suffragan of Armagh) |
| 1152 | Ireland | Abbacy nullius of Clonmacnois was promoted as Diocese of Clonmacnois |
| 1152 | Ireland | Diocese of Cong was suppressed (to Metropolitan Archdiocese of Tuam) |
| 1152 | Ireland | Abbacy nullius of Connor was promoted as Diocese of Connor (became suffragan of Armagh) |
| 1152 | Ireland | Diocese of Dublin was promoted as Metropolitan Archdiocese of Dublin (with suffragan sees Ferns, Kildare and Ossory and gained territory from Diocese of Glendalough) |
| 1152 | Ireland | Abbacy nullius of Duleek was promoted as Diocese of Duleek (became suffragan of Armagh) |
| 1152 | Ireland | Diocese of Glendalough lost territory to Metropolitan Archdiocese of Dublin |
| 1152 | Ireland | Abbacy nullius of Inniscathy was promoted as Diocese of Inniscathy (gained territory from Diocese of Ardfert and Aghadoe and became suffragan of Cashel) |
| 1152 | Ireland | Abbacy nullius of Kilfenora was promoted as Diocese of Kilfenora (became suffragan of Cashel) |
| 1152 | Ireland | Abbacy nullius of Killashee was suppressed (to Diocese of Kildare) |
| 1152 | Ireland | Abbacy nullius of Kilmacduagh was promoted as Diocese of Kilmacduagh (became suffragan of Tuam) |
| 1152 | Ireland | Abbacy nullius of Mayo was promoted as Diocese of Mayo (became suffragan of Tuam) |
| 1152 | Ireland | Abbacy nullius of Raphoe was promoted as Diocese of Raphoe (became suffragan of Armagh) |
| 1152 | Ireland | Abbacy nullius of Roscrea was promoted as Diocese of Roscrea (became suffragan of Cashel) |
| 1152 | Ireland | Abbacy nullius of Ross was promoted as Diocese of Ross |
| 1152 | Ireland | Abbacy nullius of Trim was suppressed (to Diocese of Clonard) |
| 1152 | Ireland | Diocese of Tuam was promoted as Metropolitan Archdiocese of Tuam (with suffragan sees Achonry, Annaghdown, Clonfert, Killala, Kilmacduagh, Mayo and Roscommon and gained territory from the suppressed Diocese of Cong) |
| 1152 | Northern Ireland | Diocese of Ardstraw was suppressed (to Diocese of Cinél nEógain and Ardstraw) |
| 1152 | Northern Ireland, Ireland | Archdiocese of Armagh was promoted as Metropolitan Archdiocese of Armagh (with suffragan sees Ardagh, Brefinnia, Ceanannus Mór, Cinél nEógain and Ardstraw, Clogher, Clonard, Connor, Down, Duleek, Raphoe and Louth) |
| 1152 | Northern Ireland, Ireland | Abbacy nullius of Derry was promoted as Diocese of Cinél nEógain and Ardstraw (gained territory from the suppressed Diocese of Ardstraw and became suffragan of Armagh) |
| 1152 | Northern Ireland | Abbacy nullius of Down was promoted as Diocese of Down (became suffragan of Armagh) |
| 1152 | Norway | Diocese of Hamar was established (from Diocese of Oslo) |
| 1153 | Italy | Diocese of Limosano was suppressed (to Metropolitan Archdiocese of Benevento) |
| 1153 | Norway | Diocese of Nidaros was promoted as Metropolitan Archdiocese of Nidaros (with suffragan sees Bjørgvin, Fær Øer, Gardar, Hamar, Hólar, Kirkwall, Oslo, Skálholt and Stavanger) |
| 1154 | Spain | Diocese of Vic lost territory to Metropolitan Archdiocese of Tarragona |
| 1154.10.17 | Croatia | Diocese of Zadar was promoted as Metropolitan Archdiocese of Zadar (with suffragan sees Hvar and Krk) |
| 1155 | Germany | Diocese of Oldenburg was renamed as Diocese of Lübeck |
| 1156 | Ireland | Diocese of Roscommon was renamed as Diocese of Elphin |
| 1157 | Italy | Diocese of Lipari was restored (from Diocese of Messina) |
| 1157 | Italy | Diocese of Patti was established (from Diocese of Messina) |
| 1159 | Italy | Diocese of Cirella was suppressed (to establish Diocese of San Marco) |
| 1159 | Italy | Diocese of Malvito was suppressed (to establish Diocese of San Marco) |
| 1159 | Italy | Diocese of San Marco was established (from the suppressed Diocese of Cirella and Diocese of Malvito and without ecclesiastical province) |
| 1160 | France | Diocese of Auvergne was renamed as Diocese of Clermont |
| 1160 | Germany | Diocese of Mecklenburg was renamed as Diocese of Schwerin |
| 1160 | Ireland | Diocese of Duleek was suppressed (to Diocese of Clonard) |
| 1160 | Ireland | Diocese of Roscrea was suppressed (to Diocese of Killaloe) |
| 1160 | Italy | Diocese of Capaccio was established (from the suppressed Diocese of Pesto and became suffragan of Salerno) |
| 1160 | Italy | Diocese of Pesto was suppressed (to establish Diocese of Capaccio) |
| 1160 | Spain | Diocese of Urci was suppressed |
| 1161.02.13 | Spain | Diocese of Ciudad Rodrigo was established (from Diocese of Salamanca and became suffragan of Santiago de Compostela) |
| 1162 | Italy | Diocese of Albenga lost territory to Metropolitan Archdiocese of Genova |
| 1162 | Italy | Diocese of Luni lost territory to Metropolitan Archdiocese of Genova |
| 1164 |  Finland | Diocese of Åbo was established (from Diocese of Uppsala and became suffragan of Uppsala) |
| 1164 | Sweden | Diocese of Sigtuna was suppressed (to Metropolitan Archdiocese of Uppsala and Diocese of Västerås) |
| 1164 | Sweden | Diocese of Uppsala was promoted as Metropolitan Archdiocese of Uppsala (with suffragan sees Åbo, Linköping, Skara, Strängnäs, Västerås and Växjö, gained territory from the suppressed Diocese of Sigtuna and lost territory to establish Diocese of Åbo) |
| 1165 | Portugal | Diocese of Évora was restored |
| 1166 | Italy | Diocese of Messina was promoted as Metropolitan Archdiocese of Messina (with suffragan sees Cefalù, Lipari and Patti) |
| 1169 | Italy | Diocese of Lettere was renamed as Diocese of Lettere–Gragnano |
| 1170 | Italy | Diocese of Bitetto was established (from Metropolitan Archdiocese of Bari e Canosa) |
| 1170 | Spain | Diocese of Calahorra was restored (from the suppressed Diocese of Nájera and became suffragan of Tarragona) |
| 1170 | Spain | Diocese of Nájera was suppressed (to establish Diocese of Calahorra) |
| 1172 | Spain | Diocese of Albarracin was established (from former Diocese of Segorbe) |
| 1173.02.11 | Northern Ireland, Ireland | Diocese of Cinél nEógain and Ardstraw was renamed as Diocese of Maghera, Cenél Fearadhaigh and Ardstraw |
| 1174 | Ireland | Diocese of Clonard was renamed as Diocese of Clonard |
| 1174 | Italy | Abbacy nullius of Santa Maria Nuova di Monreale was established (from Metropolitan Archdiocese of Palermo) |
| 1175 | Italy | Diocese of Alessandria was established (from Diocese of Acqui, Diocese of Asti and Diocese of Tortona and became suffragan of Milano) |
| 1175 | Poland | Diocese of Wollin was renamed as Diocese of Kamień |
| 1176 | Italy | Diocese of Mazara del Vallo lost territory to Abbacy nullius of Santa Maria Nuova di Monreale |
| 1176 | Italy | Metropolitan Archdiocese of Palermo lost territory to Abbacy nullius of Santa Maria Nuova di Monreale |
| 1177 | Italy | Diocese of Treviso lost territory to Diocese of Torcello |
| 1179 | Ireland | Diocese of Glendalough lost territory to Metropolitan Archdiocese of Dublin |
| 1179 | Italy | Archdiocese of Cosenza was promoted as Metropolitan Archdiocese of Cosenza (with suffragan see Martirano) |
| 1180 | Northern Ireland | Abbacy nullius of Dromore was promoted as Diocese of Dromore (became suffragan of Armagh) |
| 1182 | Italy | Diocese of Uselli was renamed as Diocese of Ales |
| 1183.02.05 | Italy | Abbacy nullius of Santa Maria Nuova di Monreale was promoted as Metropolitan Archdiocese of Monreale (with suffragan see Catania) |
| 1183.07.05 | Spain | Diocese of Cuenca was established (became suffragan of Toledo) |
| 1185 | Croatia | Diocese of Corbavia was established |
| 1186 |  Latvia | Diocese of Üxküll was established (from Metropolitan Archdiocese of Hamburg–Bremen and became suffragan of Hamburg–Bremen) |
| 1188 | Ireland | Diocese of Inniscathy was suppressed (to Diocese of Ardfert and Aghadoe, Diocese of Killaloe and Diocese of Limerick) |
| 1189 | Portugal | Diocese of Silves was restored |
| 1189 | Spain | Diocese of Plasencia was established (from Metropolitan Archdiocese of Santiago de Compostela and became suffragan of Santiago de Compostela) |
| 1191 | Italy | Abbacy nullius of San Salvatore Maggiore was established (from Diocese of Rieti) |
| 1191 | Italy | Diocese of Tusculum was renamed as Diocese of Tusculum–Frascati |
| 1191 | Portugal | Diocese of Silves was suppressed |
| 1192.08.03 | Italy | Diocese of Viterbo was established (from Diocese of Tuscanella and without ecclesiastical province) |
| 1193 | Scotland | Diocese of Argyll was established (from Diocese of Dunkeld) |
| 1194 | Germany | Provostry nullius of Berchtesgaden was established |
| 1194 | Italy | Diocese of Sovana lost territory to Diocese of Orvieto |
| 1196 |  Cyprus | Diocese of Famagosta was established |
| 1196 | Cyprus | Diocese of Limassol was established |
| 1196 | Cyprus | Archdiocese of Nicosia was established |
| 1196 | Cyprus | Diocese of Paphos was established |
| 1197 | England | Diocese of Bath was renamed as Diocese of Bath and Glastonbury |
| 1198 | Italy | Diocese of Assisi lost territory to Diocese of Perugia |
| 1198 | Italy | Diocese of Imola lost territory to Diocese of Bologna |
| 1199 |  Montenegro | Diocese of Bar was promoted as Metropolitan Archdiocese of Bar (with suffragan sees Arbano, Budua, Drivasto, Kotor, Pult, Sarda, Shkodrë, Svač, Trebinje and Ulcinj) |
| 1199 | Portugal | Diocese of Guarda was restored (became suffragan of Santiago de Compostela) |
| 1199.06.01 | France | Metropolitan Archdiocese of Dol was demoted as Diocese of Dol (became suffragan of Tours) |
| 1200 |  Albania | Diocese of Croia was established |
| 1200 |  Greece | Diocese of Aulon was established |
| 1200 | Greece | Diocese of Ceo was established |
| 1200 | Greece | Diocese of Cidonia was established |
| 1200 | Greece | Diocese of Daulis was established |
| 1200 | Greece | Diocese of Hierapetra was established |
| 1200 | Greece | Diocese of Malvasia was established |
| 1200 | Greece | Diocese of Modone was established |
| 1200 | Greece | Diocese of Negroponte was established |
| 1200 | Greece | Metropolitan Archdiocese of Thebæ was established |
| 1200 | Greece | Diocese of Thermopylæ was established |
| 1200 |  Iraq | Metropolitan Archdiocese of Perat-Maishan (Chaldean Rite) was suppressed |
| 1200 | Ireland | Abbacy nullius of Louth was suppressed (to Diocese of Clogher) |
| 1200 |  Israel | Diocese of Lydda was suppressed |
| 1200 | Italy | Diocese of Lesina was established (became suffragan of Benevento) |
| 1200 | Italy | Abbacy nullius of San Giusto di Susa was established (from Diocese of Torino) |
| 1200 | Italy | Diocese of San Leone was established (from Diocese of Belcastro) |
| 1200 |  Jordan | Metropolitan Archdiocese of Petra was suppressed |
| 1200 |  North Macedonia | Diocese of Dardania was restored |
| 1200 | Palestine | Metropolitan Archdiocese of Scythopolis was suppressed |
| 1200 | Spain | Diocese of Málaga was suppressed |
| 1200 |  Syria | Diocese of Arethusus was suppressed |
| 1200 |  Turkiye | Archdiocese of Edessa was suppressed |
| 1200 | Turkiye | Archdiocese of Heraclea was demoted as Titular Metropolitan See of Heraclea |
| 1200 | Turkiye | Diocese of Lampsacus was suppressed |
| 1200 | Turkiye | Metropolitan Archdiocese of Sebastia was suppressed |
| 1200 | Turkiye | Diocese of Sebastopolis was suppressed |
