Like it or loathe it, Bing Crosby immortalised it, and there's rarely a night of celebration where someone doesn't break into a bar of two of the song. Now, a descendant of the composer of Galway Bay will join the President, Mrs McAleese, among the guests at a gala banquet to mark NUI Galway's 150th anniversary.
His name is Mr Sean Colahan, he lives in Australia, and it was Dr Tadhg Foley, one of the university's lecturers, who tracked him down. He is related to Arthur Whistler Colahan, a Galway medical graduate who penned those immortal lines, If you ever go across the sea to Ireland, it may be at the closing of your day.
Not travelling quite so far for the dinner on Saturday night is Cdr William Leslie-King, of Oranmore Castle, Co Galway, and his daughter, the artist Leonie King. Cdr King is the great-grandson of Prof William King, who was appointed professor of mineralogy, geology and natural history at what was then known as Queen's College, Galway, in 1849.
His most memorable contribution to science was the term "Neanderthal man", and he was the first to recognise that the skull cap found in a Neanderthal cave in Bohemia belonged to an early hominid and not an ape.
Prof Foley was assigned the task of tracing descendants of original staff and students for the occasion. He was assisted by Ms Fiona Bateman, a PhD student. The trail led them to such people as Mr Colin Keane, now living in Dublin, and his wife, Ms Sally Figgis, of the book-selling and publishing family.
Mr Keane is great-grandnephew of Christopher Marrett Keane, from Ennis, Co Clare, who entered the university at the tender age of 15 and received a BA with first class honours in 1853 and a diploma in elementary law. He was presented with a gold medal and the sum of £10.
Macnas will greet the guests as they arrive for the evening in Aras na Mac Leinn, and music before and after dinner will be performed by the Galway traditional group, Dordan, and the 21-piece Black Magic Jazz Orchestra. Dordan, which has just released its latest album, Celtic Aire, on the US Narada label, will perform a specially-commissioned anthem for the occasion which was written by its harpist, Kathleen Loughnane.
Also as part of the birthday celebrations, the university's law faculty will on Friday host a major lecture on restorative justice which will be delivered by Judge Frederick McElrea of New Zealand. A direct descendant of one of the college's first graduates, he is acknowledged to be a world expert on the subject.
Advocates of restorative justice believe the legal system should concentrate on confronting offenders with the consequences of their wrongdoing, and the impact on the offending victim, rather than focusing solely on punishment.
The lecture is open to the public and takes place in NUI Galway's Cairnes Theatre at 7 p.m.