These two sons of the late Tony Ryan inherited his stake in Ryanair, though most of it was sold since the IPO in 1990, enabling them to bank some 260m.
Wicklow-based entrepreneur and philanthropist Declan invests in start-ups such as Coindrum but has also had continued success building up or backing low-cost airlines across the world including Singapore-based Tiger Airways, Allegiant Air in the US and VivaAerobus in Mexico. The family's Irelandia Investments sold a 49pc stake in the latter last November, which was estimated to be worth 226m.
Property interests reportedly in Britain, Poland, Asia and Mexico are also likely to have done well in the past year. Shane is a successful bloodstock farmer, owning stud farms in Tipperary and Kentucky.