The family stake of Kildare native Ned Guinness (49) in drinks giant Diageo is up about 7pc over the past year to €315m.
But he has other assets, including BGL Golf in Britain, BGL Estates and Adventure Leisure, which between them own more than 20 golf courses, tenanted farms and land in the wealthy Surrey commuter belt outside London, as well as gated residential developments, a country club, a listed manor house and 850 moorings in Chichester Harbour.
The holding company for these interests had a turnover of Â£28.7m in 2017, made a pre-tax profit of Â£1.6m and had Â£38.5m of net assets, though it seems the properties may be worth a lot more than that.
Guinness, also known as Lord Iveagh, lives on the 22,500-acre Elveden estate in Suffolk, on which he grows onions and potatoes for Sainsbury's, McDonalds and Walkers Crisps. Its Elveden Hall has featured in a James Bond film and Netflix's The Crown. He uses either a modern 4x4 or a battered little Nissan Micra to get around his land, but also keeps a green 1928 vintage Rolls-Royce.
Here, his brother Rory runs a farm in Co Meath, while there is also a philanthropic interest in The Iveagh Trust, which is building affordable homes in Dublin and has almost 1,500 apartments and hostel places in the capital.
Ned also backed Irish cloud communications firm Blueface, which merged with US rival Star2Star last year in a $500m deal. It's likely he made a tidy profit and took some cash off the table after the deal, but is believed to have retained a stake in the merged entity.
In Canada, the Guinnesses also own British Pacific Properties, which develops apartments and multi-million dollar mansions that are some of Canada's most expensive properties in exclusive West Vancouver on about 1,000 acres that are available to develop on its 2,000-acre holdings. The land has been in the family since 1931, and plots were steadily sold off to developers over the years.