An Ulster judge who has rubbed shoulders with Dublin rockers U2 will today be sworn into one of the top legal positions in Northern Ireland.
Mr Justice Deeny is among three judges who have been appointed by the Queen as Lord Justices of Appeal.
The others are Mr Justice Stephens and Mr Justice Treacy. They will take up their offices at the Royal Courts of Justice in Belfast.
Sir Ben Stephens was educated at Manchester University and called to the Bar of Northern Ireland in 1977.
He has also been called to the Bar of England and Wales and Ireland and he took silk in 1996. He was appointed a High Court judge in 2007.
Sir Seamus Treacy was educated at Queen's University, Belfast, and he was called to the Bar in Northern Ireland in 1979, 13 years before he was called to the Bar in Ireland.
He took silk in 1999 and went on to become a High Court judge in 2007.
Sir Donnell Deeny, who was born in Lurgan, was educated at Trinity College Dublin and QUB before he was called to the Bar here in 1974, taking silk 15 years later.
He became a High Court judge in 2004.
But away from the law, Sir Donnell has also had a busy and prominent role in a number of fields in Northern Ireland.
He was an Alliance councillor for four years from 1981 and in 1983 he became High Sheriff of Belfast - the first Catholic to hold office in the city since partition.
He was also the chairman of Opera Northern Ireland for five years until 1993, when he moved to a similar position in the Arts Council of Northern Ireland until 1998.
In June 1987 when U2 played a hastily-arranged concert at the King's Hall, Sir Donnell was spotted at the gig and at an after-show party.
It was later revealed that he had been friends with the band's manager Paul McGuinness for years.
Two years ago McGuinness wrote an article for a newspaper in which he described Sir Donnell as his best friend from their schooldays in the south at Clongowe Woods College in Co Kildare.
He said that in October 1968 Sir Donnell introduced him to Paolo Tullio, who went on to become one of the Republic's most high-profile food critics and chefs.
He added: "Donnell said to me one day 'There's a very unusual guy in my legal science class, I think you'd like him'."
Mr McGuinness said he, Donnell Deeny and Paolo Tullio became friends immediately.
The food critic died two years ago.
Sir Donnell has been pro vice chancellor at Trinity since 2014.
As a student he had been active in a number of university bodies including its magazine.
He also represented Trinity in the Irish Times National Debating Championship and won three times.
Among the other posts that Sir Donnell has held are as a trustee of the Ulster Museum in Belfast and as a director of the Tyrone Guthrie centre in Co Monaghan and Hearth Social Housing in Belfast.
He was the founding chairman of the Ireland Professorship of Poetry, which sends a distinguished poet to Trinity College Dublin, Queen's University, Belfast, and University College Dublin in triennial procession.
Sir Donnell chairs the United Kingdom Spoliation Advisory Panel, which advises the Government and the museum and galleries sector throughout the UK on the return of art plundered during the Nazi era.
Up until last year he also served as the president of the Ulster Architectural Heritage Society.