The selection of a Chieftain was with the permission and by the advice of the nobles, both lay and ecclesiastical of the Clan. Those eligible for the high office were required to be of the blood of the original conqueror or acquirer of the territory. Selection was confined to the "Dearbhfine" - a specified family group spanning four generations. Other requirements were that the successful candidate should be free from blemish and of a fit age to lead his people in the field.
The inauguration ceremony had both its religious and civil sides. The former was conducted by the successor of St. Colm Cille viz. The bishop of Derry and the Coarb of Kilmacrennan, in the nearby Abbey. The presence of O'Friel, the Coarb concerned, was indispensible as he was the actual Inaugurator.
The civil ceremony took place on the Rock of Doon in the presence of the Clan. The ruler-elect removed his footwear and stood in the imprint of the feet of the first Chieftain that was cut into the Inauguration Stone. O'Clery, the Ullamh, came forward and read aloud a brief summary of the laws and customs in accordance with which the Clan should be governed. An oath was then administered that these ancient practices would be preserved inviolate.
This done, the candidate set asside the sword and was presented with 'An Slat Bhan', a straight white rod, as an emblem of purity and rectitude and a reminder that his judgement should be unbiased and that he should be pure and upright in his actions. It was also an indication that his people would be obedient to him and that no other weapon would be required to command them. A sub-Chieft next replaced one of the wearer's sandals as a token of submission and threw the other over his shoulder for luck.
Then, "amid the clang of bucklers, music of harps and cheers of the whole assembly", the Chieftain was proclaimed by the Inaugurator who, in a loud voice, pronounced the surname O'Domhnaill only, which was taken up by the Clergy, sub-chiefts, Freeholders and finally by the whole gathering.
Having been thus inaugurated the new Chieftain stepped down from the stone and turned around thrice forwards and thrice backwards (in honour of the Holy Trinity) to view his territories and show himself to his people.
(The ornamented Inauguration stone was kept in Kilmacrennan Abbey, where it survived until c. 1775 when it was smashed to smithereens by an anti-Irish bigot).
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