It was written by one of my favourite Irish men Brendan Beham. If one needed qualifications to be an Irish hero, then Behan was over qualified. Born to fiercely nationalist parents, his Brother Dominic was one of Eire's greatest songwriters. Brendan joined the IRA and was arrested on his first failed mission. Was sentenced to death later commuted to Life, then released under a general amnesty. But while in the despised Mountjoy jail he developed his love for writing. Including the only song credited to him (not as some believe by his brother) The Auld triangle, written for his play The Quare Fella, (about a prisoner awaiting his execution) and surely about his own experiece of Prison. He was also a great raconteur and became a darling of chat shows, in Ireland, England but mostly in America and Canada and was outrageusly critical of Irish religion and government. Heavily alcoholic too and a devout womaniser. His wit was much feted and often quoted.
My favourite quote is on a handwritten note sent to a bar owner in my home town in Ireland, under a framed picture of Behan in the tiny bar it says "fellas, I've just arrived in Canada and saw a sign saying 'drink Canada Dry' I'm about to do my feckin best!" Sadly the drink took him at the height of his fame