The County Fermanagh insurance magnate Sean Quinn has lost his place as the wealthiest man in Ireland, according to US finance magazine Forbes.
Sean Quinn said the money the family lost in a bank investment was "hurtful"
The Forbes list, which tracks the rising and falling fortunes of the world's richest people, estimates Mr Quinn to have lost a staggering $4.5 bn, leaving him 468th on the list with $1.5 bn.
The Dublin mobile phone mogul Denis O'Brien has taken top spot in Ireland with a fortune of $2.2bn.
62-year-old Sean Quinn famously started with a single quarry on his father's farm, selling sand and gravel to local builders, before building up a huge business empire.
Today he and three of his five children run interests spanning a range of industries including construction supply, glass manufacturing, insurance, hotels and pubs.
Forbes said Mr Quinn's controversial investment in Anglo-Irish Bank left a big hole in his finances.
When the Irish government nationalised the bank in January, Mr Quinn told RTE his losses were more than 1 bn euro.
One trick is to endear his firm to masses by lowering prices and upping philanthropy
"I think if anybody had said 10 years ago, you're going to invest in glass, radiators, plastics, packaging, Russia, India, Ukraine, the Irish banks, some people would say you're safe in the Irish banks but I'm not too sure if you're safe in Russia," he said.
"The money we lost is hurtful, and we do not like it and I'm not trying to dismiss it or downsize it, but at the end of the day a lot of people in Ireland have lost a lot more in share dealings and in their value than we have."
Forbes said it was "a rare misstep for mogul known for traditional ways: skipped university to work a quarry on his father's farm and still doesn't use a cell phone."
Denis O'Brien, meanwhile, has double cause for celebration. Not only is he number one in Ireland, his old adversary Sir Anthony O'Reilly has been dropped from the list of billionaires.
Denis O'Brien is listed by Forbes as Ireland's wealthiest man
Sir Anthony has been fending off attempts by Mr O'Brien to get more control of his Independent News and Media group, which includes the Irish Independent and Belfast Telegraph.
While O'Brien suffered a loss on his investment in that company, his core telecoms business has held up well, providing him with a fortune of $2.2bn.
Forbes describes the married father-of four as "a colorful, cussing cell phone mogul" who operates in dozens of Caribbean islands and is quickly expanding in the South Pacific "despite coups, riots and government threats to nationalize".
The magazine adds: "One trick is to endear his firm to masses by lowering prices and upping philanthropy.
"Angry mobs in Haiti's food riots last year spared his phone stores from burning and looting out of respect for the 'Company of the People'.