Date | Country | Change |
| 1001 |  Hungary | Metropolitan Archdiocese of Esztergom was established (from Diocese of Nitra, Diocese of Passau and Diocese of Regensburg) |
| 1002 |  Italy | Diocese of Suelli was established (became suffragan of Cagliari) |
| 1004 |  Germany | Diocese of Merseburg was restored (from Metropolitan Archdiocese of Magdeburg and became suffragan of Magdeburg) |
| 1004 | Hungary | Diocese of Eger was established (became suffragan of Esztergom) |
| 1004 | Hungary | Diocese of Vác was established (became suffragan of Esztergom) |
| 1006 | Italy | Diocese of Gualdo Tadino was suppressed (to Diocese of Nocera Umbra) |
| 1006 | Italy | Diocese of Plestia was suppressed (to Diocese of Foligno, Diocese of Nocera Umbra and Diocese of Spoleto) |
| 1007.11.01 | Germany | Diocese of Bamberg was established (from Diocese of Eichstätt and Diocese of Würzburg and became suffragan of Mainz) |
| 1009 | Hungary | Diocese of Győr was established (became suffragan of Esztergom) |
| 1009 | Hungary | Diocese of Pécs was established (became suffragan of Esztergom) |
| 1009 | Hungary | Diocese of Veszprém was established (became suffragan of Esztergom) |
| 1009 |  Romania | Diocese of Byhor was established |
| 1009 | Romania | Diocese of Transilvania was established |
| 1010 | Hungary | Diocese of Kalocsa was established (became suffragan of Esztergom) |
| 1010 |  Spain | Diocese of Badajoz was suppressed |
| 1010 |  Sweden | Diocese of Växjö was established |
| 1013 | Italy | Abbacy nullius of Sansepolcro was established (from Diocese of Città di Castello) |
| 1014 | Sweden | Diocese of Skara was established (became suffragan of Hamburg) |
| 1014.02.14 | Italy | Diocese of Bobbio was established (from Diocese of Piacenza, Diocese of Tortona and Abbacy nullius of San Colombano) |
| 1015 | Italy | Diocese of Bomarzo was suppressed (to Diocese of Bagnoregio) |
| 1015 | Italy | Diocese of Tortiboli was established (became suffragan of Benevento) |
| 1015 |  Poland | Diocese of Kołobrzeg was suppressed (to Metropolitan Archdiocese of Gniezno and Diocese of Kujawy–Pomorze) |
| 1019 | Italy | Diocese of Eca was suppressed (to establish Diocese of Troia) |
| 1019 | Italy | Diocese of Troia was established (from the suppressed Diocese of Eca) |
| 1020 | Italy | Diocese of Giovinazzo was established (became suffragan of Bari) |
| 1020 | Italy | Diocese of Molfetta was established (became suffragan of Bari) |
| 1023 | Italy | Diocese of Castellaneta was established (became suffragan of Taranto) |
| 1023 | Italy | Diocese of Mottola was established (became suffragan of Taranto) |
| 1024 | Spain | Diocese of Tui was suppressed (to Diocese of Iria Flavia) |
| 1025 | Italy | Diocese of Oppido Mamertina was established (from Diocese of Tauriano and became suffragan of Reggio Calabria) |
| 1028 | Germany | Diocese of Zeitz was renamed as Diocese of Naumburg |
| 1030 | Hungary | Diocese of Csanád was established (became suffragan of Esztergom) |
| 1030 | Italy | Diocese of Brindisi–Oria was promoted as Metropolitan Archdiocese of Brindisi–Oria (with suffragan see Monopoli and lost territory to establish Diocese of Monopoli) |
| 1030 | Italy | Diocese of Monopoli was established (from Diocese of Brindisi–Oria and became suffragan of Brindisi–Oria) |
| 1030 | Italy | Diocese of Umbriatico was established |
| 1030 |  Norway | Diocese of Nidaros was established |
| 1030 | Spain | Diocese of Pamplona lost territory to Diocese of Bayonne |
| 1032 | Italy | Diocese of Venafro was restored (became suffragan of Capua) |
| 1033 |  France | Diocese of Saint-Jean-de-Maurienne lost territory to Diocese of Torino |
| 1033 | Italy | Diocese of Civita Castellana was established (from the suppressed Diocese of Faleri and without ecclesiastical province) |
| 1033 | Italy | Diocese of Faleri was suppressed (to establish Diocese of Civita Castellana) |
| 1034 | Spain | Diocese of Palencia was restored (became suffragan of Toledo) |
| 1035 | Spain | Diocese of León exchanged territory with Diocese of Palencia |
| 1035 | Spain | Diocese of Palencia exchanged territory with Diocese of León |
| 1036 | Italy | Diocese of Ischia was established (became suffragan of Napoli) |
| 1038 |  Ireland | Diocese of Dublin was established (from Abbacy nullius of Glenndálocha and became suffragan of Canterbury) |
| 1039 | Italy | Diocese of Dragonara was established (became suffragan of Benevento) |
| 1040 |  England | Diocese of Cornwall was suppressed (to Diocese of Crediton) |
| 1040 | Italy | Diocese of Luni lost territory to Diocese of Massa Marittima e Populonia |
| 1040 | Italy | Diocese of Muro Lucano was established |
| 1040 | Spain | Diocese of Roda lost territory to Diocese of Urgell |
| 1042 | Italy | Diocese of Montepeloso was suppressed (to Diocese of Tricarico) |
| 1047 | Italy | Abbacy nullius of San Giovanni in Venere was established (from Diocese of Chieti) |
| 1049 | Italy | Diocese of Monteverde was established (became suffragan of Salerno) |
| 1050 |  Croatia | Diocese of Knin was established (became suffragan of Split) |
| 1050 | Croatia | Diocese of Nona was restored (from Diocese of Zadar) |
| 1050 | Croatia | Diocese of Traù was established (became suffragan of Split) |
| 1050 | England | Diocese of Crediton was renamed as Diocese of Exeter |
| 1050 | Germany | Diocese of Ratzeburg was established (from Diocese of Oldenburg and became suffragan of Hamburg) |
| 1050 | Italy | Diocese of Cefalù lost territory to Diocese of Palermo |
| 1050 | Italy | Diocese of Cerveteri was suppressed (to Diocese of Porto) |
| 1050 | Italy | Diocese of Massa Lubrense was established (from Diocese of Sorrento) |
| 1050 | Italy | Diocese of Melfi was established (without ecclesiastical province) |
| 1050 | Italy | Diocese of Montemarano was established (became suffragan of Benevento) |
| 1050 | Italy | Diocese of Ostuni was established (from Metropolitan Archdiocese of Brindisi–Oria and became suffragan of Brindisi–Oria) |
| 1050 | Italy | Diocese of Sorrento was promoted as Metropolitan Archdiocese of Sorrento (with suffragan see Castellammare di Stabia and lost territory to establish Diocese of Massa Lubrense and Diocese of Vico Equense) |
| 1050 | Italy | Diocese of Sulci was restored |
| 1050 | Italy | Diocese of Vico Equense was established (from Diocese of Sorrento) |
| 1050 |  Scotland | Diocese of Abernathy was suppressed |
| 1050 | Sweden | Diocese of Linköping was established (from Diocese of Skara and became suffragan of Hamburg) |
| 1050 | Sweden | Diocese of Munktorp was established (became suffragan of Hamburg) |
| 1052 | Ireland | Abbacy nullius of Seir Kieran was renamed as Abbacy nullius of Aghaboe |
| 1053 | Italy | Diocese of Atella was suppressed (to establish Diocese of Aversa) |
| 1053 | Italy | Diocese of Aversa was established (from the suppressed Diocese of Atella and Diocese of Liternium and became suffragan of Napoli) |
| 1053 | Italy | Diocese of Liternium was suppressed (to establish Diocese of Aversa) |
| 1054 | Italy | Diocese of Luni lost territory to Diocese of Pisa |
| 1054 |  Turkiye | Patriarchal See of Constantinople was suppressed |
| 1055 | Scotland | Diocese of Birsay was established |
| 1056 |  Iceland | Diocese of Skálholt was established (became suffragan of Hamburg) |
| 1056 | Italy | Diocese of Acerra was established (from the suppressed Diocese of Suèssola and became suffragan of Napoli) |
| 1056 | Italy | Diocese of Suèssola was suppressed (to Diocese of Sant’Agata de’ Goti and to establish Diocese of Acerra) |
| 1057 | Italy | Diocese of Lecce was established (became suffragan of Otranto) |
| 1057 | Italy | Diocese of Senigallia lost territory to Diocese of Fossombrone |
| 1058 | England | Diocese of Ramsbury was suppressed (to Diocese of Sherborne) |
| 1058.03.24 | Italy | Diocese of Marsico Nuovo was established (from former Diocese of Grumentum and became suffragan of Salerno) |
| 1058.03.24 | Italy | Diocese of Martirano was established (became suffragan of Salerno) |
| 1058.03.24 | Italy | Diocese of Policastro was established (from former Diocese of Bussento and became suffragan of Salerno) |
| 1059 | Croatia | Diocese of Alba maritima was established |
| 1059 | Italy | Diocese of Acerenza was promoted as Archdiocese of Acerenza |
| 1059 | Italy | Diocese of Eclena was suppressed (to establish Diocese of Frigento) |
| 1059 | Italy | Diocese of Fiorentino was established (became suffragan of Benevento) |
| 1059 | Italy | Diocese of Frigento was established (from the suppressed Diocese of Eclena and became suffragan of Benevento) |
| 1059 | Italy | Diocese of Guardialfiera was established (became suffragan of Benevento) |
| 1059 | Italy | Diocese of Montecorvino was established (became suffragan of Benevento) |
| 1059 | Italy | Diocese of Nicotera was restored (from Diocese of Tropea) |
| 1059 | Italy | Diocese of Vulturara was established (became suffragan of Benevento) |
| 1059 | Spain | Diocese of León exchanged territory with Diocese of Palencia |
| 1059 | Spain | Diocese of Palencia exchanged territory with Diocese of León |
| 1059.05 | Italy | Diocese of Cosenza was promoted as Archdiocese of Cosenza |
| 1060 |  Denmark | Diocese of Børglum was established (from Diocese of Ribe and became suffragan of Hamburg) |
| 1060 | Denmark | Diocese of Viborg was established (from Diocese of Ribe and became suffragan of Hamburg) |
| 1060 | Italy | Diocese of Amiterno was suppressed (to Diocese of Rieti) |
| 1060 | Italy | Diocese of Boiano was established (became suffragan of Benevento) |
| 1060 | Italy | Diocese of Civitate was established |
| 1060 | Italy | Diocese of Gravina was restored |
| 1060 | Italy | Diocese of Rapolla was established (without ecclesiastical province) |
| 1060 | Norway | Diocese of Selja was established |
| 1060 | Sweden | Diocese of Dalby was established (from Diocese of Roskilde) |
| 1060 | Sweden | Diocese of Lund was established (from Diocese of Roskilde) |
| 1060 | Sweden | Diocese of Sigtuna was established |
| 1062 |  Albania | Diocese of Sapë was established |
| 1063 |  Czechia | Diocese of Olomouc was established (from Diocese of Praha and became suffragan of Mainz) |
| 1063 | Italy | Diocese of Trani was promoted as Metropolitan Archdiocese of Trani |
| 1063 | Scotland | Diocese of Mortlach was established |
| 1064 | Italy | Diocese of Siponto was promoted as Archdiocese of Siponto |
| 1064 |  Portugal | Diocese of Colimbria was renamed as Diocese of Coimbra |
| 1065 | Italy | Diocese of Carini lost territory to Metropolitan Archdiocese of Palermo |
| 1065 | Italy | Diocese of Lilibeo lost territory to Metropolitan Archdiocese of Palermo |
| 1065 | Italy | Diocese of Palermo was promoted as Metropolitan Archdiocese of Palermo (gained territory from Diocese of Carini, Diocese of Lilibeo and Diocese of Termini Imerese) |
| 1065 | Italy | Diocese of Termini Imerese lost territory to Metropolitan Archdiocese of Palermo |
| 1067 | Sweden | Diocese of Dalby was suppressed (to Diocese of Lund) |
| 1068.04.13 | Italy | Archdiocese of Acerenza was promoted as Metropolitan Archdiocese of Acerenza (with suffragan sees Gravina, Matera, Potenza, Tricarico, Tursi and Venosa) |
| 1069 | Spain | Diocese of Tui was restored (from Diocese of Iria Flavia) |
| 1070 | England | Diocese of Dunwich was renamed as Diocese of Thetford |
| 1070 | France | Diocese of Mâcon lost territory to Abbacy nullius of Cluny |
| 1070 | Italy | Diocese of Bisceglie was established |
| 1070 | Italy | Diocese of Bova was established (from Diocese of Locri) |
| 1070 | Italy | Diocese of Dolia was established |
| 1070 | Italy | Diocese of Gallura was restored |
| 1070 | Norway,  Bouvet Island | Diocese of Oslo was established |
| 1071 | Spain | Metropolitan Archdiocese of Lugo was demoted as Diocese of Lugo (gained territory from Diocese of Oviedo and became suffragan of Braga) |
| 1071 | Spain | Diocese of Oviedo lost territory to Diocese of Lugo |
| 1071.03.06 |  Austria | Diocese of Gurk was established (from Metropolitan Archdiocese of Salzburg and became suffragan of Salzburg) |
| 1072 | England | Diocese of Dorchester was renamed as Diocese of Lincoln |
| 1072 | Germany | Diocese of Bremen was suppressed (to Metropolitan Archdiocese of Hamburg–Bremen) |
| 1072 | Germany | Metropolitan Archdiocese of Hamburg was renamed as Metropolitan Archdiocese of Hamburg–Bremen (gained territory from the suppressed Diocese of Bremen) |
| 1073 | Italy | Diocese of Ampurias was established (became suffragan of Torres) |
| 1073 | Italy | Diocese of Bosa was established (from Metropolitan Archdiocese of Sinis-Tharros and became suffragan of Torres) |
| 1073 | Italy | Diocese of Castro was established (became suffragan of Torres) |
| 1073 | Italy | Diocese of Sorres was established (became suffragan of Torres) |
| 1073 | Italy | Metropolitan Archdiocese of Torres was restored (with suffragan sees Ampurias, Bisarcio, Bosa, Castro and Sorres) |
| 1074 |  Isle of Man | Diocese of Man was established (from Diocese of Dublin) |
| 1074 | Italy | Diocese of Olivolo was renamed as Diocese of Castello |
| 1075 | England | Diocese of Chester was established (from the suppressed Diocese of Lichfield and became suffragan of York) |
| 1075 | England | Diocese of Chichester was established (from the suppressed Diocese of Selsey) |
| 1075 | England | Diocese of Elmham was suppressed |
| 1075 | England | Diocese of Lichfield was suppressed (to establish Diocese of Chester) |
| 1075 | England | Diocese of Sarum was established (from the suppressed Diocese of Sherborne) |
| 1075 | England | Diocese of Selsey was suppressed (to establish Diocese of Chichester) |
| 1075 | England | Diocese of Sherborne was suppressed (to establish Diocese of Sarum) |
| 1075 | Poland | Diocese of Płock was established |
| 1075 | Spain | Diocese of Auca was suppressed (to establish Diocese of Burgos–Auca) |
| 1075 | Spain | Diocese of Burgos–Auca was established (from the suppressed Diocese of Auca) |
| 1076 | Italy | Diocese of Nusco was established (from Metropolitan Archdiocese of Benevento and became suffragan of Salerno) |
| 1077 | Romania | Diocese of Byhor was renamed as Diocese of Oradea Mare |
| 1077 | Spain | Diocese of Jaca was established (from the suppressed Diocese of Sasabe) |
| 1077 | Spain | Diocese of Osma lost territory to Diocese of Nájera |
| 1077 | Spain | Diocese of Pamplona lost territory to Diocese of Nájera |
| 1077 | Spain | Diocese of Sasabe was suppressed (to establish Diocese of Jaca) |
| 1078 | Italy | Abbacy nullius of San Michele Arcangelo di Montescaglioso was established |
| 1078 | Italy | Abbacy nullius of Santa Maria ad Abbadia Alpina was established |
| 1080 |  Faroe Islands | Diocese of Fær Øer was established (from Metropolitan Archdiocese of Hamburg–Bremen) |
| 1080 | Italy | Diocese of Conversano was established (from Metropolitan Archdiocese of Bari and became suffragan of Bari) |
| 1080 | Italy | Diocese of Conza was promoted as Metropolitan Archdiocese of Conza (with suffragan sees Lacedonia, Monteverde, Muro Lucano and Sant’Angelo dei Lombardi) |
| 1080 | Italy | Diocese of Forum Traiani was suppressed (to establish Diocese of Santa Giusta) |
| 1080 | Italy | Diocese of Locri was renamed as Diocese of Gerace |
| 1080 | Italy | Diocese of Lacedonia was established (became suffragan of Conza) |
| 1080 | Italy | Diocese of Santa Giusta was established (from the suppressed Diocese of Forum Traiani) |
| 1080 | Italy | Diocese of Sant’Angelo dei Lombardi was established (became suffragan of Conza) |
| 1080 | Italy | Diocese of Ugento was established |
| 1080 | Norway | Diocese of Selja was renamed as Diocese of Bjørgvin |
| 1081 | Italy | Metropolitan Archdiocese of Reggio Calabria lost territory to Diocese of Bova and Diocese of Oppido Mamertina |
| 1081 | Italy | Abbacy nullius of Santissimo Salvatore (Italo-Albanese Rite) was established |
| 1081.02.04 | Italy | Diocese of Mileto was established (from the suppressed Diocese of Vibo Valentia and without ecclesiastical province) |
| 1081.02.04 | Italy | Diocese of Vibo Valentia was suppressed (to establish Diocese of Mileto) |
| 1082 | Italy | Diocese of Matera was suppressed (to Metropolitan Archdiocese of Acerenza) |
| 1082 | Italy | Diocese of Troina was established (from former Diocese of Lipari, former Diocese of Messina, former Diocese of Taormina and former Diocese of Tindari) |
| 1086 | Italy | Diocese of Ravello was established (from Metropolitan Archdiocese of Amalfi and without ecclesiastical province) |
| 1086 | Italy | Diocese of Siracusa was restored (from former Diocese of Catania and former Diocese of Lentini) |
| 1087 | Spain | Diocese of Valpuesta was suppressed (to Diocese of Burgos–Auca) |
| 1087 | Spain | Diocese of Valpuesta was suppressed (to Diocese of Burgos–Auca) |
| 1088 | Italy | Diocese of Agrigento was restored (from Metropolitan Archdiocese of Palermo and former Diocese of Tricala and without ecclesiastical province) |
| 1088 | Spain | Diocese of Armentia was suppressed (to Diocese of Nájera) |
| 1088 | Spain | Diocese of Álava was suppressed (to Diocese of Nájera) |
| 1088.08.23 | Italy | Diocese of Treba was suppressed (to Diocese of Anagni) |
| 1090 | England | Diocese of Wells was renamed as Diocese of Bath |
| 1090 | Italy | Diocese of Acerno was established (became suffragan of Salerno) |
| 1090 | Italy | Diocese of Bisaccia was established (became suffragan of Conza) |
| 1090 | Italy | Abbacy nullius of Nardò was established (from Diocese of Gallipoli) |
| 1090 | Italy | Diocese of Ploaghe was established (became suffragan of Torres) |
| 1090 |  Serbia | Archdiocese of Bač was established |
| 1091 | Portugal | Diocese of Portucale was suppressed (to Metropolitan Archdiocese of Braga) |
| 1091.06.01 | Spain | Archdiocese of Tarragona was promoted as Metropolitan Archdiocese of Tarragona (with suffragan sees Burgos–Auca, Jaca, Pamplona, Urgell and Vic) |
| 1092.03.09 | Italy | Diocese of Catania was restored (from Diocese of Siracusa) |
| 1092.04.21 | Italy | Diocese of Pisa was promoted as Metropolitan Archdiocese of Pisa (with suffragan sees Accia, Mariana and Nebbio) |
| 1093 | Croatia | Diocese of Zagreb was established (from former Diocese of Sisak and became suffragan of Esztergom) |
| 1093 | Italy | Diocese of Blera was suppressed (to Diocese of Tuscanella) |
| 1093 | Italy | Diocese of Civitavecchia was suppressed (to Diocese of Tuscanella) |
| 1093 | Italy | Diocese of Mazara del Vallo was established (from Metropolitan Archdiocese of Palermo and became suffragan of Palermo) |
| 1093 | Italy | Metropolitan Archdiocese of Oristano was established (from the suppressed Metropolitan Archdiocese of Sinis-Tharros and with suffragan see Uselli) |
| 1093 | Italy | Metropolitan Archdiocese of Sinis-Tharros was suppressed (to establish Metropolitan Archdiocese of Oristano) |
| 1093.10.03 | Italy | Diocese of Tauriano was suppressed (to Diocese of Mileto) |
| 1094 | England | Diocese of Thetford was renamed as Diocese of Norwich |
| 1094 | Italy | Diocese of Amantea was suppressed (to Diocese of Tropea) |
| 1094.03.23 | France | Diocese of Arras was restored (from Diocese of Cambrai) |
| 1095.03.14 | Spain | Diocese of Burgos–Auca was renamed as Diocese of Burgos |
| 1095.12.05 | Spain | Diocese of Iria Flavia was suppressed (to establish Diocese of Santiago de Compostela) |
| 1095.12.05 | Spain | Diocese of Santiago de Compostela was established (from the suppressed Diocese of Iria Flavia and became suffragan of Braga) |
| 1096.12.27 | Ireland | Diocese of Waterford was established (from Abbacy nullius of Lismore and became suffragan of Canterbury) |
| 1098 | Italy | Diocese of Messina was restored (from the suppressed Diocese of Troina) |
| 1098 | Italy | Abbacy nullius of Santissima Trinità di Mileto was established |
| 1098 | Italy | Diocese of Troina was suppressed (to establish Diocese of Messina) |
| 1098 | Turkiye | Titular Patriarchal See of Antioch was restored |
| 1098.05.11 | Spain | Diocese of Huesca–Jaca was restored (from the suppressed Diocese of Jaca) |
| 1098.05.11 | Spain | Diocese of Jaca was suppressed (to establish Diocese of Huesca–Jaca) |
| 1098.07.20 | Italy | Diocese of Satriano was established (became suffragan of Conza) |
| 1099 |  Israel | Diocese of Lydda was established |
| 1099 | Italy | Diocese of Forum claudii was renamed as Diocese of Carinola |
| 1099 | Italy | Diocese of Città della Pieve was suppressed (to Diocese of Chiusi) |
| 1099 | Italy | Archdiocese of Siponto was promoted as Metropolitan Archdiocese of Siponto (with suffragan see Vieste) |
| 1099 |  Palestine,  Cyprus, Israel,  Jordan | Patriarchal See of Jerusalem was restored |
| 1099 | Turkiye | Archdiocese of Mopsuestia was restored |
| 1099.05.04 | Spain | Diocese of Complutum was suppressed (to Metropolitan Archdiocese of Toledo) |
| 1100 | Albania | Diocese of Arbano was established |
| 1100 | Albania | Diocese of Sarda was established |
| 1100 |  Bosnia and Herzegovina | Diocese of Bosnia was established |
| 1100 | France | Diocese of Châlon-sur-Saône lost territory to Metropolitan Archdiocese of Besançon |
| 1100 | France | Abbacy nullius of Saint-Oyand de Joux was established (from Metropolitan Archdiocese of Besançon, Metropolitan Archdiocese of Lyon, Diocese of Châlon-sur-Saône, Diocese of Langres and Diocese of Mâcon) |
| 1100 | Israel | Diocese of San Giovanni d’Acri was established |
| 1100 | Italy | Diocese of Acquaputrida was suppressed (to Diocese of Frigento) |
| 1100 | Italy | Diocese of Andria was established (from Metropolitan Archdiocese of Trani and became suffragan of Trani) |
| 1100 | Italy | Diocese of Biccari was suppressed |
| 1100 | Italy | Diocese of Limosano was established (became suffragan of Benevento) |
| 1100 | Italy | Abbacy nullius of Massa Carrara was established (from Diocese of Lucca) |
| 1100 | Italy | Diocese of Rosella was suppressed |
| 1100 | Italy | Territorial Abbacy of Subiaco was established (from Diocese of Tivoli) |
| 1100 | Italy | Diocese of Tocco Caudio was suppressed |
| 1100 | Italy | Metropolitan Archdiocese of Trani lost territory to Metropolitan Archdiocese of Nazareth |
| 1100 | Italy | Diocese of Trevi was suppressed (to Diocese of Spoleto) |
| 1100 | Palestine | Metropolitan Archdiocese of Nazareth was established (gained territory from Metropolitan Archdiocese of Trani) |
| 1100 | Scotland | Diocese of Moray was established |
| 1100 | Spain | Diocese of Osma was restored (became suffragan of Toledo) |
| 1100 | Spain | Diocese of Valencia was suppressed |
| 1100 | Spain | Diocese of Ávila was restored |
| 1100 | Sweden | Diocese of Uppsala was established (from Metropolitan Archdiocese of Hamburg–Bremen and became suffragan of Hamburg–Bremen) |
| 1100 | Sweden | Diocese of Munktorp was renamed as Diocese of Västerås |
| 1100 |  Syria | Metropolitan Archdiocese of Damascus was suppressed |
| 1100 | Turkiye | Metropolitan Archdiocese of Ancyra was suppressed |
| 1100 | Turkiye | Metropolitan Archdiocese of Cesarea in Cappadocia was suppressed |
| 1100 | Turkiye | Archdiocese of Colossæ was suppressed |
| 1100 | Turkiye | Metropolitan Archdiocese of Iconium was suppressed |
| 1100 | Turkiye | Metropolitan Archdiocese of Laodicea was suppressed |
| 1100 | Turkiye | Metropolitan Archdiocese of Melitene was suppressed |
| 1100 | Turkiye | Metropolitan Archdiocese of Neocæsarea was suppressed |
| 1100 | Turkiye | Metropolitan Archdiocese of Nicæa was suppressed |
| 1100 | Turkiye | Archdiocese of Parium was suppressed |
