Former investment banker Barry O'Callaghan was a high-flying technology tycoon, building up Riverdeep and then Houghton Mifflin Harcourt into one of the world's biggest online publishers before everything came crashing down during the financial crisis. Bondholders took control of the debt-laden company, wiping out his fortune. However, O'Callaghan has been rebuilding his fortune, through an e-learning business in China. Last year he sold his majority stake in Rise Global to Bain Capital for $140m. He also owns the Cliff House Hotel.
O'Callaghan's plans for a fee-paying international baccalaureate school in Leopardstown, south county Dublin, were recently given the green light by council chiefs. The 800-pupil school plans to open in 2018 and will be operated by Nord Anglia Education, a 2bn US-quoted group which has more than 40 schools around the world.