— Don, in Roscommon, [140], [374]
O’Connors, the, [56], [57], [61], [62], [69], [86]
— of Offaly, the, [86], [120], [121], [129], [130], [175], [177], [213], [348], [385], [401]-[403]
O’Corrin, James, Bishop of Killaloe, [305]
Octavian de Palatio, Archbishop of Armagh (1480-1513), [104], [108]
O’Dempseys, the, of Clanmalier (Portnahinch in Queen’s Co. and Upper Philipstown in King’s Co.), [251]
O’Dogherty, chief of Innishowen in Donegal, [140], [274], [345]
O’Donlevy, chief of Uladh, [53]
O’Donnell, chief of Tyrconnel, [62]
— Donnell Oge, chief of Tyrconnel, [63]