11. Viscount Portman & Family
£950m
Portman Estates
2008: £1,300m (-£350m)
Viscount Portman appointed former Cluttons managing partner Gareth Clutton as the new chief executive of the Portman Estate late last year.
Clutton took over from Hugh Seaborn, now working for Viscount Cadogan in Chelsea, who for eight years worked wonders revitalising the 110 acres owned by Portman north of Oxford Circus.
The work is not finished. A revamp of Portman Square in central London is planned, following an estate-wide review. Portman, 51, has been trying to improve the image of his central London inheritance since he took over the estate on his father's death in 1999.
Owned by a series of complex family trusts, the Portman estate was slower than the other big London landowners to start improvements because many of its properties were out on long leases. These are coming to an end and the estate is taking a more proactive role in development, spending £40m on an investment programme that includes projects such as Portman Village, the name for two shopping streets in the heart of the estate.
As well as the London estate, Portman owns a rag bag of rather obscure assets, including 17,000 acres at Wagga Wagga in New South Wales, Australia.
Other assets include a share in commercial properties in Manhattan in New York and Palm Beach in Florida. There are few signs of family wealth in its two companies - Brickleton Group and Portman Settled Estates - with over £700,000 net assets between them in 2007-08.
Despite the improvements on the estate, we cut its valuation to £900m in the current climate.
We add another £50m for family assets including its Herefordshire estate and a holiday home in Antigua.