Declan and Shane Ryan and family
Rank 2017

Investments in airline start-ups around the world have seen Ryan, 53, and family more than quadruple the €176m they made as co-founders of Ryanair. Their Irelandia Investments has had stakes in low-cost start-ups in Singapore, Thailand and Las Vegas, and made €168m profit in November selling its 49% share of Mexico's VivaAerobus. It plans a South and Central American carrier via its Panama-registered Grupa Viva and already controls VivaColombia. Shane, 45, brother of Wicklow-based Declan, is also a shareholder in Irelandia. A racehorse enthusiast, he inherited from father Tony the 1,000-acre Castleton Lyons stud in Kentucky and is renovating the former French embassy in Dublin, which he bought for €4m in 2013. The other beneficiaries of Irelandia are Cillian, Claudia, Danielle – who owns Roads, a perfume, publishing and entertainment company – and Cameron, children of the late Cathal Ryan, Declan’s eldest brother. The wider family also invests in commercial property, biotechnology, software and venture capital funds worth €280m. In November, the family sold for €12m the Lyons Estate, Co Kildare, in which Tony had reportedly invested €80m. Declan is a generous philanthropist, having donated more than €25m via his One Foundation.