Seamus Mulligan and family
Rank 2017

Athlone-based Mulligan, 56, has a €138m stake in Jazz Pharmaceuticals. The Dublin-based Nasdaq-quoted company develops drugs to treat brain conditions such as narcolepsy. A graduate of Trinity College Dublin, Mulligan sold €3.2m shares in Jazz last August, taking his total proceeds from share sales in the company beyond €198m. He has re-invested some of this in Dublin-based Adapt Pharma, which focuses on the American market. The former Elan executive is backing the €7m Waterford whiskey distillery project in his native county. He has also invested in the Four Seasons Hotel in Prague and property in London.