Donegal Castle: seat of the O'Donnell dynasty (see below text for more images of interior and exterior)

The Royal Household and Administration

The administrative organisation of the Tyrconnell realm depended heavily on the application of and recourse to ancient Brehon Law, including leadership succession by elective competition, under the principles of tanistry within an immediate kinship group, the derbhfine, and on the hereditary functional roles of particular tributary families.  Within this framework, the Royal Household was known in Gaelic as "Lucht Tighe" and comprised several offices that were performed on a hereditary basis for over four centuries largely by the heads and members of these families:

Lector and Inaugurator of the Chieftancy:  O’Friel

Gallowglass and Standard-Bearers:  McSweeney

Marshall of Hosts, of Cavalry:  O’Gallagher

Custodians of the Cathach of St. Columba:  McRoarty

Historians and Scribes:  O’Clery 

Brehons or Judges: Breslin and McGilshenan

Bards and Poets: Ward

Physicians: Dunlevy

Stockmen/Cattle Drovers:  Timoney

Other customary tributary family positions included the following:

Bailiffs:  McGettigan

Harper:  O’Ciaragain

Steward:  MacLinchy

Seneschal: McGonnell

Butler:  O’Cullinane

Servant:  Crawford

Dynastic alliances

In late Gaelic Ireland, far from the in-breeding of some other cultures, a complicated web of considerable genetic diversity emerged as a result of the increasing frequency of intermarriage between Gaelic, Norman and Old English stock. 

This was the underlying reality behind the old adage of the relative newcomer becoming Hiberniores ipsis Hibernis, more Irish that the Irish themselves, adopting not only Gaelic language, dress and manners, but adapting names as well, e.g. FitzMaurice becoming Mac Muiris. Gaelic lords fostered their sons not only to other families and clans, but even to those of Norman and Old English origins, and vice versa.

Inevitably, dynastic marriage became equally cross-cultural, as both sons and daughters became the agents of strategic alliances between great families of different origins. Both fosterage and dynastic marriages strengthened the socio-political power-base for members of the derbhfine to compete for the position of Tánaiste, tanist, and eventually succession as Taoiseach, chieftain. The strongest or most capable, and not always the eldest heir, succeeded on the enabling basis of prevailing political support, and the prospect of military supremacy.