Ruhan (52) hit the headlines last year more than a high-profile divorce from his wife of 18 years. The property tycoon, who grew up in Athenry, Co Galway, made a fortune from data centres, with his Sentrum business selling three data centres to Digital Realty for €850m in 2012.
He has also had hotel interests, picking up the 32-strong Thistle chain in 2003 for €800m in a highly leveraged deal. These were turned into luxury apartments and flipped for huge profits.
He owns assets ranging from the four-star Cannizaro House in Wimbledon, an African game reserve and a company that lays undersea cables. Ruhan is also a serious petrol head. There's a collection of classic cars too, including a 1962 Jaguar E type.
He was on the board of the Lotus F1 team in 2013 and ran it for two years before Renault took control at the end of 2015. He is a highly competitive driver too, winning the GT Cup at Brands Hatch in 2011. There's a €6.5m-valued mansion at Chalifont St Peter in Buckinghamshire. In his divorce proceedings, he gave his address as the yacht Babylon, moored off Mallorca.