Chronology of Catholic Dioceses:Ireland

See a list of abbreviations used in this list. See also our listing of current ecclesial jurisdictions.

Regarding the first several centuries, the history of dioceses in Ireland cannot be read in the same way as that of most other countries. A major point about Irish hierarchical history is that there was very little power invested in the dioceses, and hardly any independent emphasis was put on them. This was due to the huge proliferation of monastic communities, to the point where bishops where always referred to as abbots, and that gave them their real power, such as in Armagh. Soon after his death in 492, the monastic system, which Patrick had himself partly initiated, had become the settled form of ecclesiastical organisation in Ireland. The number of tribes into which the country was divided, and the fierce inter-tribal jealousy that prevailed at all times, rendered this system the more desirable. Each tribe had its own monastic establishment with a portion of the tribe lands set apart for its endowment, and in most of these centres a bishop was to be found, frequently (but not necessarily) the ruler of the community.

This fact, together with the thick layers of legends and myths, makes it very difficult to say much with precision and certainty about the development of the diocesan structure in Ireland.

The first truly comprehensive attempt to reorganize the hierarchical structure of Ireland along continental lines, were made at the Synod of Rathbreasil (Rath-Breassail) in 1111. But it was only the Synod of Kells in 1152 which established a durable pattern. The hierarchical territorial structure of the Catholic Church in Ireland today is, by and large, very similar to what was determined in 1152.

- CT (input from Mr. Michael Breslin, and from CE)

400-500

Killaloe - Ireland

431

Emly - Ireland

433?

Trim - Ireland

441~

Aghagower - Ireland

445

Armagh / Ard Macha - Ireland

450

Elphin - Ireland

454

Clogher - Ireland

480~ (maybe later: mentioned 659)

Connor - Ireland

490

Kildare (first bishop consecrated; abbey built 470) - Ireland

500~

Kilmore - Ireland

500-600

Down - Ireland

500-600

Kerry and Aghadoe - Ireland

500-600

Killala - Ireland

500-600

Roscrea - Irland

514 (or before 974?)

Dromore - Ireland

520~

Tuam - Ireland

524~

Árd Carna / Ardcarne (first bishop supposed to have died in 524) - Ireland

549

Ossory - Ireland

552

Meath - Ireland

560

Achonry - Ireland

570

Ross - Ireland

580

Cloyne - Ireland

600-700

Kilfenora - Ireland

600-700

Limerick - Ireland

603~

Movilla / Moville (first mentioned in the sources about 603) - Ireland

610-620

Kilmacduagh - Ireland

625

Ferns (first mentioned in the sources about 625) - Ireland

616

Lusk (first mentioned in the sources about 616) - Ireland

626

Cong - Ireland

633

Dublin - Ireland

639~

Nendrum (first mentioned in the sources about 639) - Ireland

650-850?

Aghagower (gradually absorbed by Mayo) - Ireland

654~

Clonard (first mentioned in the sources about 654) - Ireland

659~ (or 637)

Lismore - Ireland

659~

Devenish (first mentioned in the sources about 659) - Ireland

660~

Glendalough (first mentioned in the sources about 660) - Ireland

665

Lemanaghan (only mentioned in the sources about 665) - Ireland

667~

Mayo (Abb., later D) - Ireland

672~

Clonenagh (mentioned in the sources only about 672) - Ireland

676~

Inishbofin (first mentioned in the sources about 676) - Ireland

680~

Ardstraw (first mentioned in the sources about 680) - Ireland

687~

Taghmon (only mentioned in the sources about 687) - Ireland

692~

Sleaty (only mentioned in the sources about 692) - Ireland

707~

Ardstraw (vacant?, last mentioned in early sources about 707, but seems to have been considered a diocese until about 1266) - Ireland

711~

Lynally (first mentioned in the sources about 711) - Ireland

713~

Clonmacnois / Clonmacnoise (first mentioned in the sources about 713) - Ireland

713~

Inishbofin (last mentioned in the sources about 713) - Ireland

731~

Raymoghy (only mentioned in the sources about 731) - Ireland

732~

Mayo (first mentioned in the sources about 732) - Ireland

739

Lambay (only mentioned in the sources about 739) - Ireland

741~

Aughrim (first mentioned in the sources about 741) - Ireland

744~

Lissan (only mentioned in the sources about 744) - Ireland

744~

Seirkieran (first mentioned in the sources about 744) - Ireland

746~

Trim (first mentioned in the sources about 746) - Ireland

750~

Fore (first mentioned in the sources about 750) - Ireland

751~

Aughrim (last mentioned in the sources about 751) - Ireland

752~

Clooncraff (only mentioned in the sources about 752) - Ireland

756~

Methus Troim (only mentioned in the sources about 756) - Ireland

773~

Movilla / Moville (last mentioned in the sources about 773) - Ireland

781~

Ardbraccan (first mentioned in the sources about 781) - Ireland

783~

Duleek (first mentioned in the sources about 783) - Ireland

784~

Iniskeen (first mentioned in the sources about 784) - Ireland

788~

Lorrha (first mentioned in the sources about 788) - Ireland

788~

Rahugh (only mentioned in the sources about 788) - Ireland

789~

Aghaboe (only mentioned in the sources about 789) - Ireland

789~

Clondalkin (first mentioned in the sources about 789) - Ireland

791~

Finglas (first mentioned in the sources about 791) - Ireland

792~

Tallaght (first mentioned in the sources about 792) - Ireland

796~

Finglas (last mentioned in the sources about 796) - Ireland

796~

Scattery Island (first mentioned in the sources about 796/797) - Ireland

807~

Clonfert (first mentioned 807, legendary origin about 550) - Ireland

808~

Linns (only mentioned in the sources about 808) - Ireland

814~

Trillick (only mentioned in the sources about 814) - Ireland

817~

Roscommon (first mentioned in the sources about 817) - Ireland

822~

Birr (first mentioned in the sources about 822) - Ireland

822~

Louth (first mentioned in the sources about 822) - Ireland

823~

Bangor (first mentioned in the sources about 823/824) - Ireland

823~

Lough Kinale (only mentioned in the sources about 823) - Ireland

825~

Downpatrick (first mentioned in the sources about 825) - Ireland

837~

Clonkeen (first mentioned in the sources about 837) - Ireland

837~

Monasterbroice (first mentioned in the sources about 837) - Ireland

838~

Kilbrew (only mentioned in the sources about 838) - Ireland

838~

Kildalkey (only mentioned in the sources about 838) - Ireland

840~

Clones (first mentioned in the sources about 840) - Ireland

843~

Castledermot (first mentioned in the sources about 843) - Ireland

845~

Dunleer (first mentioned in the sources about 845) - Ireland

853~

Birr (last mentioned in the sources about 822) - Ireland

856~

Laraghbryan (only mentioned in the sources about 856) - Ireland

865~

Leighlin (maybe abandoned within some years?) - Ireland

866~

Lorrha (last mentioned in the sources about 866) - Ireland

867~

Kildkeer (only mentioned in the sources about 867) - Ireland

870~

Castlekerran (only mentioned in the sources about 870) - Ireland

870~

Devenish (last mentioned in the sources about 870) - Ireland

871~

Killeigh (first mentioned in the sources about 871) - Ireland

872~

Dulane (first mentioned in the sources about 872) - Ireland

873~

Nendrum (last mentioned in the sources about 873) - Ireland

874~

Ardagh (first mentioned 874, legendary origin about 450) - Ireland

876~

Cork (first mentioned 876, legendary origin about 600) - Ireland

877~

Lynally (last mentioned in the sources about 877) - Ireland

879~

Dromiskin (only mentioned in the sources about 879) - Ireland

881~

Clonkeen (last mentioned in the sources about 881) - Ireland

882~

Clondalkin (last mentioned in the sources about 882) - Ireland

887~

Cloyne (first mentioned 887, legendary origin about 580) - Ireland

895~

Terryglass (first mentioned in the sources about 895) - Ireland

900-1000

Cashel - Ireland

900~

Castledermot (last mentioned in the sources about 900) - Ireland

903~

Dunmanoge (only mentioned in the sources about 903) - Ireland

903~

Trevet (only mentioned in the sources about 903) - Ireland

905~

Dunleer (last mentioned in the sources about 905) - Ireland

907~

Fennor (only mentioned in the sources about 907) - Ireland

912~

Seirkieran (last mentioned in the sources about 912) - Ireland

917~

Killeshin (only mentioned in the sources about 917) - Ireland

918~

Aran (only mentioned in the sources about 918) - Ireland

922~

Inan (only mentioned in the sources about 922) - Ireland

927~

Inish Caltra (first mentioned in the sources about 927) - Ireland

929~

Derry (maybe abandoned within some years?) - Ireland

931~

Trim (last mentioned in the sources about 931) - Ireland

933~

Timahoe (only mentioned in the sources about 933) - Ireland

945~

Dulane (last mentioned in the sources about 945) - Ireland

950~

Fiddown (only mentioned in the sources about 950) - Ireland

950~

Louth (vacant?, last mentioned in early sources about 950, but seems to have been considered a diocese until about 1266) - Ireland

953~

Bangor (last mentioned in the sources about 953) - Ireland

953~

Inish Caltra (last mentioned in the sources about 953) - Ireland

954~

Killeigh (last mentioned in the sources about 954) - Ireland

956~

Downpatrick (last mentioned in the sources about 956) - Ireland

959~

Raphoe (first mentioned 959, legendary origin 5th century) - Ireland

963~

Clones (last mentioned in the sources about 963) - Ireland

963~

Iniskeen (last mentioned in the sources about 963) - Ireland

964~

Kilcullen (only mentioned in the sources about 964) - Ireland

965~

Terryglass (last mentioned in the sources about 965) - Ireland

966~

Monasterbroice (last mentioned in the sources about 966) - Ireland

966~

Tuamgraney (only mentioned in the sources about 966) - Ireland

968~

Tallaght (last mentioned in the sources about 968) - Ireland

969~

Kells (first mentioned in the sources about 969) - Ireland

974~

Scattery Island (last mentioned in the sources about 974) - Ireland

979~

Cloneogher (only mentioned in the sources about 979) - Ireland

1096

Waterford - Ireland

1111

Armagh (Metr.) - Ireland

1111

Cashel (Metr.) - Ireland

1111

Duleek (confirmed as diocese) - Ireland

1111

Glendalough (confirmed as diocese) - Ireland

1111

Roscrea (suppressed, incorporated in Killaloe) - Ireland

1114?~

Cong (extinct, later incorporated in Annaghdown) - Ireland

1121

Dublin (incorporated into Glendalough) - Ireland

1130

Dublin (reestablished, detached from Glendalough) - Ireland

1130

Leighlin (revived?) - Ireland

1152

Árd Carna / Ardcarne (suppressed, territory incorporated in Roscommon, in Ardagh, and Clonmacnois) - Ireland

1152

Ardbraccan (incorporated in Meath) - Ireland

1152

Armagh (Metr., reconstituted) - Ireland

1152

Cashel (Metr., reconstituted) - Ireland

1152

Clonard (incorporated in Meath) - Ireland

1152

Donshaghlin / Dunshaughlin (incorporated in Meath) - Ireland

1152

Dublin (Metr.) - Ireland

1152

Fore (incorporated in Meath) - Ireland

1152

Kells (incorporated in Meath) - Ireland

1152

Kildare (name settled, previously frequently also called Leighlin) - Ireland

1152

Kilfenora (confirmed as diocese) - Ireland

1152

Kilmacduagh (confirmed as diocese) - Ireland

1152

Mayo (recognized as diocese) - Ireland

1152

Meath (reestablished, comprised of the eight old Irish dioceses of Clonard, Duleek, Kells, Trim, Ardbraccan, Donshaglin / Dunshaughlin, Slane, and Fore / Foure) - Ireland

1152

Roscommon (suppressed, incorporated in Elphin) - Ireland

1152

Slane (incorporated in Meath) - Ireland

1152

Trim (incorporated in Meath) - Ireland

1152

Tuam (Metr.) - Ireland

1158

Derry (revived?) - Ireland

1169-1175?

Ardmore (incorporated into Lismore) - Ireland

1170-1200~

Annaghdown (detached from Tuam) - Ireland

1204

Glendalough (incorporated in Dublin) - Ireland

1209

Mayo (vacant, and temporarily incorporated into Tuam, revived on and off later) - Ireland

1266~

Ardstraw (seems to have been incorporated into Derry) - Ireland

1266~

Louth (seems to have been incorporated into Armagh) - Ireland

1363

Waterford and Lismore (united) - Ireland

1439

Down and Connor (united) - Ireland

1324

Annaghdown (incorporated in Tuam, but allowed a certain autonomy as wardenship since 1485) - Ireland

1631

Mayo (incorporated into Tuam by papal decree; the English had forced through this some time before) - Ireland

1678

Kildare and Leighlin (united) - Ireland

1718

Emly (incorporated in Cashel) - Ireland

1729

Clonmacnois (incorporated in Ardagh) - Ireland

1750

Kilfenora (incorporated in union with Kilmacduagh) - Ireland

1831

Galway (detached from Tuam) - Ireland

1883

Galway and Kilmacduagh (united) - Ireland

1883

Kilfenora (nominally still a distinct diocese, but administratively joined to Galway and Kilmacduagh - Kilfenora remains nevertheless in theory suffragan of Cashel, in spite of Galway and Kilmacduagh being suffragan of Tuam) - Ireland

1952

Kerry (new name, previously Kerry and Aghadoe) - Ireland

1958

Cork and Ross (united) - Ireland