Hennessy was born in Tralee, County Kerry, Ireland. He left school at the age of eleven and a half.[2] His first job was as a messenger boy, and it was then that he discovered that it was important to be able to read. He later worked at building sites in London. He was unable to read or write, but still enjoyed his library of books. [3]

[edit] A renowned songwriter as well as performer, Hennessy wrote several songs that became hits for other singers including 'Don't Forget your Shovel', made famous by Christy Moore, and 'All the Lies that You Told Me', recorded by Frances Black Had recently gone into the studio to record an album with both Luka Bloom and Christy Moore sharing vocals on one of the tracks.[4]Hennessy died on 11 December 2007 in a London hospice, aged 62. He was reported to have died from mesothelioma, which has been attributed to his younger years spent working on building sites in London.[5][4]