The O Mahony Septs

(extracted from David O’Mahony’s “Septs of the O’Mahonys” in The O’Mahony Journal, 1974, pp. 3-4.)

Mahon succeeded his father, Cian, as King of the Nine Territories in 1014.

He probably lived at Rath Rathlinn at Garranes six miles north of Bandon at Templemartin.

The branches of the sept descended from Mahon are as follows:

1. O Mathuna Fionn:                                       (O Mahony Fionn) descended from Diarmuid Mor I

    O Mathuna Iarathaigh                                Diarmuid died (1350+)

    O Mathuna an Iarthair                               Western O Mahonys Schull, Ballydehob

    Clann Diarmada                                         Diarmuid’s Family (Ardtennant was their main castle)

1 (a) Sliocht Taidgh                           

        a sub-sept of O Mathuna Fionn

2. Sliocht Diarmada

    or An Sliocht Meirigeach                            Courtmacsherry, Butlerstown, Lislevane

    from Diarmuid Og. Diarmuid had               (Also known as O Mathuna Laidir)  

    two sons. One had no children, but            (Found at Barryroe, and also in Kerry)

    the other, Teig Meirgeach, had eight          (Teig Meirgeach is the reputed progenetor of the

    sons.                                                            Kerry branches, of Dromore. Dunloe and Brosna

            after 1327AD)

3. Sliocht Cill na Gluaire                                (O Mahony of Kilnaglory lived in the area from

   A sub-set of Sliocht Diarmada                     Ballincollig) and from there to Ballinhassig,

            Carrigaline to Tracton)

   Descended from Diarmuid Mor II                (Donal arrived at “Barrett’s country from Ardtennant

   greatgrandson of Diarmuid Mor I               or Rosbrin after his father’s death c. 1327AD )

4. O Mathuna Uibh Floinn Luadh                  From Goleen, to Caheragh and Drimoleague

   Descended from Teig an Oir,                       (Some buried at Kilmichael) also called the Iffanloe

   brother of Diarmuid Mor II                         (Some  known as the O Mahony Ban or White and is

            derived from Liam Ban O Mahony c. 1750, and William

            was still used as a family name in this branch until the

            20^th century).

5. Clann Finghin(Fineen)                               Located in West Muskerry

    Descended from Finighin (died 1327AD)   They are also known as Kearneys.

    grandson of Diarmuid Mor I

   (also called Clann Fineen na

   Ceithirne) or of the troops

6. Clann Chonchubhar (Conor)                      Found at Bandon, Kilmurray and Kilmichael from

    Descended form a brother of                      Tiarna Cineal na mBeice (Lord of Kinealmeaky)

    Diarmuid Mor I                                           (Connor O Mahonys known also as O Mahony Cnos)

7. O Mathuna Cairbreach                               O Mahonys of Carbery, Rosscarbery

8. An Clann Ruadh (O Mathuna Rua)             This branch had land at Kilmurray

   Descended from Donnchadha                      (also known as the O Mahony Roe or Rua)

   Rua a descendant of Finighin

9. O Mathuna Caol (Slender)                          May possibly still be found in the area of Leamcon

From Finghin Caol of Leamcom                    Castle. Finghin Caol lived c. 1500 AD and

            belonged to the Western sept. ( Fineen the Slender)

Other branches of unclear origin

O Mahony Bui (Yellow)

O Mathuna an Airigid                                     Found in East Kilmurray

The O Mahony Keane                                     (possibly an unrelated group of families who retained

            the name Cian). Cian is common in Kilmurray.

The O Mahony Fane                                       (possibly O Mathuna Fian or the Wild O Mahonys?)

There are also branches in Mallow, Fermoy and in Mitchelstown in Co. Cork and in Newcastle

West in Limerick.

Recent yDNA research has shown that not all who bear the name (although related to others of the

name O Mahony) carry the O Mahony yDNA.  The web of kinship was a wide one, and the

 development of this  web of relationships promises  to be an interesting story that will no doubt

 unfold in the fullness of time.