Another family surnamed Ó hAonghusa were found at Ros Ailithir, in the Kingdom of Desmond. It is from this family that the founder of Hennessy brandy, Richard Hennessy of Mallow and Cognac (1720–1800), descended. Richard's descendant, Kilian Hennessy (1907–2010), was a French business magnate and patriarch of the Hennessy cognac company.
- "Irish Ancestors/ Surnames". irishtimes.com. Retrieved 16 January 2014.
- "Irish Family Names - Hennessy". irelandseye.com. Retrieved 16 January 2014.
- "Hennessy Coat of Arms / Hennessy Family Crest". 4crests.com. Retrieved 16 January 2014.