The family of Lord Ballyedmond is the wealthiest in Northern Ireland with a fortune of £1.4 billion, a new survey has found.
The late pharmaceuticals mogul, who founded Newry-based Norbrook laboratories in 1969, was killed in a helicopter crash near his Gillingham estate near Norfolk two months ago.
He is survived by his wife Mary, a solicitor, his barrister daughter Caroline, and sons Edward and James.
His billionaire family – ranked in 66th place out of 104 – is the only local entry in this year's Sunday Times Super-Rich list, which was published yesterday.
Meanwhile, at number 22, mobile phones and investment guru Denis O'Brien, who is worth £3.854 billion, has emerged as Ireland's richest man.
With 13 million subscribers, his Bermuda-based Digicel Group and associated mobile phone companies operate in 31 countries worldwide.
The 56-year-old married father-of-four owns 29.9% of Independent News and Media (INM), valued at £55m, 19 radio stations in Latvia, Bulgaria and Jordan and eight in the UK.
This year represents the first time the number of billionaires living in Britain and Ireland has surpassed the 100 mark.
The 104 entries – more than triple the number from a decade ago – boast a combined wealth of more than £301 billion.
It means Britain has more billionaires per head of population than any other country, while London's total of 72 sterling billionaires is more than any other city in the world.
Indian-born brothers Sri and Gopi Hinduja top the list of the UK's wealthiest billionaires with a fortune of £11.9 billion.
The London-based pair, who run the global conglomerate Hinduja Group, saw their wealth rise by £1.3 billion in the last year, the study found.
They replaced Russian business magnate Alisher Usmanov at the top after the Arsenal shareholder saw his fortune fall to £10.65 billion.
The richest Briton, the Duke of Westminster, is ranked 10th on the list after his fortune rose to £8.5 billion.
Last year, 88 billionaires were living in the UK, worth a total of more than £245 billion, according to the Sunday Times Rich List.
That figure compares to 30 billionaires living in Britain in 2004, with a combined wealth of £65 billion. It is the first time since 2008 that the minimum wealth of the 50 richest people in the country has exceeded £1.5 billion.
A decade ago, a personal fortune of £700 million was needed to be among Britain's 50 wealthiest people, whereas the entry point to the UK top 50 today is £1.7 billion.
The combined wealth of the Britain's super rich is now ahead of the pre-recession levels of 2008, when the total wealth of the UK's 75 billionaires was £201 billion.
The 2014 Sunday Times Rich List will be published on May 18.
The UK's ultra-wealthy top 10
1. Sri and Gopi Hinduja (Industry & Finance) = £11.9bn
2. Alisher Usmanov (Mining & Investment) = £10.65bn
3. Lakshmi Mittal and family (Steel) = £10.25bn
4. Len Blavatnik (Investment, Music & Media) = £10bn
5. Ernesto and Kirsty Bertarelli (Pharmaceuticals) = £9.75bn
6. John Fredriksen and family (Shipping & Oil Services) = £9.25bn
7. David and Simon Reuben (Property & Internet) = £9bn
8. Kirsten and John Rausing (Inheritance & Investment) = £8.8bn
9. Roman Abramovich (Oil & Industry) = £8.52bn
10. The Duke of Westminster (Property) = £8.5bn