O’Byrnes, the, of Wicklow, [25], [266], [298]
O’Cahan, or O’Kane, of Londonderry County, [40], [116]
O’Callaghan of Duhallow, in Cork, [135], [145], [237]
O’Carroll, Sir William, chief of Ely, [148]
— Mulrony, [266]
— Thady, [147]
O’Carrolls, the, of Ely, in King’s County, [112]
O’Connor, Brian, chief of Offaly, [7]
O’Connor, Cahir, and Cormac, sons of Brian, [134]-[137], [254]