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Denis O’Brien

O’Brien joins the billionaire’s club today, the youngest Irish citizen to do so and the quickest to make a billion. Last month the Dubliner, 49, pulled off his second financial coup in seven years, gaining £375m in cash when his Caribbean mobile phone company, Digicel, was refinanced. More importantly, it left him with an even bigger future pot — he won full control of Bermuda-registered Digicel Group, worth more than £726m. This, along with two Pacific Rim and South American operations — which he owns the bulk of and are worth more than £100m — is one of the world’s fastest-growing mobile operations, with 4.1m customers in 22 countries. Despite his father letting slip that he’d often had a hard time getting his son out of bed in time to attend lectures, O’Brien was also awarded an honorary law degree by his alma mater, University College Dublin. Like many Irish entrepreneurs, the sports lover is generous with his money. This month O’Brien gave the Ireland cricket team almost £100,000 for reaching the Super Eight stages of the World Cup against the odds and he strongly supports charities such as Amnesty International and Frontline, which supports human rights defenders at risk. O’Brien’s rise to billionaire status effectively dates back to the millennium, when he made more than £175m selling his stake in Irish phone company Esat Telecom and used this to fund Digicel. He had already bought the £40m Quinta do Lago resort on the Algarve prior to the sale and used £37m to buy the PGA European Tour. He has also invested in more than 10 Irish high-tech start-ups, with mixed results, and in property in central London. O’Brien has continued to build his stake to 5%, worth £84m, in Independent News & Media, and is aiming to double his holding. The 2.1% stake he bought last year in Aer Lingus, worth £20m, has been less profitable. His other assets include fishing trawlers and he has a share of Aergo Capital, an £8m Dublin aircraft leasing business with 36 jets. He stepped down from several directorships in November, including a lucrative one at the Bank of Ireland, but bought into the Irish fuel business of Shell. He also has a stake in Glasgow Celtic football club. Although a tax resident overseas, O’Brien has paid £23m for a home in Ballsbridge, Dublin — the second-highest price paid for a property in Ireland. Investment entrepreneurs never know when to leave the casino, he once said. So far, it seems, the dice are still rolling in his favour.