- A family who were established at Ballymacmoy, Killavullen, county Cork, by the mid 18th century. One branch of the family settled at Cognac in France and produced Hennessy brandy. The Hennessys held land from the Nagles in the parish of Monanimy, county Cork and a collection of archives in the James Hardiman Library, NUI, Galway, document a legal case 1771-1831 between the Hennessys and the ffrenches of Rahasane, county Galway, who had inherited some of the Nagle lands. At the time of Griffith's Valuation James Hennessy held at least three townlands in the parish of Monanimy. The Hennessy estate amounted to 863 acres in the 1870s.