Net worth: £365 million Age: 59 The Duke (pictured here with his daughter on her wedding day) owes his wealth to inheriting assets, such as Alnwick Castle which has been in the family for more than 700 years. He also has an extensive estates portfolio, including 120,000 acres in Northumberland.Net worth: £425 million Age: 61 Townshend is the only other person, other than the Queen, to be allowed to own swans. Her wealth mainly comes from estate companies and farming. Some of the most lucrative estates she owns is 20 acres of land around the affluent Holland Park area in London.Net worth: £580 million Age: 76 Francis Ronald Egerton is the 7th Duke of Sutherland and most of his wealth comes from his art collection and owning 12,000 acres in the Scottish Borders and East Anglia. Net worth: £650 million Age: 80 Rothschild chairs RIT Capital Partners, which he built into a £2.57 billion company, after departing from the family bank. He also retains vast amounts of land surrounding Waddesdon Manor estate in Buckinghamshire before it was given to the National Trust in 1957. His personal wine collection of 15,000 bottles dates as far back as 1870. Net worth: £685 million Age: 54 Andrew Ian Henry Russell is the 15th Duke of Bedford and is heir to two family companies as well as house and grounds valued at £150 million. His art collection is extensive and the 24 Canalettos, paintings by artist Giovanni Antonio Canal, are worth £450 million alone. However, like most aristocrats, he makes a lot of money off lucrative estates in London, such as 180 buildings in the affluent Bloomsbury. Net worth: £750 million Age: 72 British orphans, Prince Jonathan and Princess Gesine (pictured), were adopted by Royal Navy officer Frank Pogson and London-born Princess Orietta Doria-Pamphilj — from an Italian noble family. Their inheritance accounts for all their wealth as they own a palace in Genoa, an art collection and the Palazzo Doria Pamphilj in Rome.Net worth: £854 million Age: 46 Ned Guinness, a descendant of Arthur who invented the drink in 1759, sold the family mansion in Farmleigh, Dublin's Phoenix Park, which he grew up in 1999. But his vast wealth landed on him after he became 4th Earl of Iveagh in 1992 as he inherited £62 million in Guinness shares. He and his family stake's in Diageo, which owns Guinness, is worth £200 million. Net worth: £870 million Age: 72 Like most of the aristocrats on this list, the Duke of Devonshire's wealth comes from owning large amounts of estate, such as Chatsworth House in Derbyshire and a 30,000-acre Yorkshire estate. He also has an art collection worth £900 million.Net worth: £1 billion Age: 48 Jonathan Harmsworth, the Viscount, took control over the Daily Mail & General Trust in 1998 when his father died. The family stake is worth £710 million and the rest of his wealth derives from dividends and property in London and the southwest of England.Net worth: £1.58 billion Age: 82 Crown Princess Marie-Chantal is rich because her father Robert Miller made his fortune through cofounding the Hong Kong-based Duty Free Shoppers chain in 1960. She then married Pavlos, the son of former King Constantine II of Greece, who was deposed in 1973.Net worth: £1.89 billion Age: 57 Christopher Edward Berkeley Portman, the 10th Viscount Portman, owns an estate which includes 110 acres of land in central London, which gives him and his family huge amounts of wealth. On the estate, the group let out residential properties across some of the most affluent areas in London, including shops in Baker Street. Net worth: £3.63 billion Age: 80 The Baroness, eldest of four daughters of the late Lord Howard de Walden, increased the family's fortune by £400 million in 2014 to 2015, mainly due to their control of 90 acres of central London land.Net worth: £5.7 billion Age: 79 Charles Gerald John Cadogan cultivated a massive fortune through the property company Cadogan Group. In 2014, the group bought almost 200 properties. He's been a huge beneficiary of the London property-price boom as the Cadogan Group owns 93 acres in Chelsea — one of the capital's prime locations. Im 2015, net assets at the Cadogan Group rose to £5.2 billion ($7.48 billion), says The Sunday Times.Net worth: £9.35 billion Age: Gerald Grosvenor, 64 (at the time of the ranking calculation). Hugh Grosvenor, 25. When the ranking was initially calculated in April this year, the Sixth Duke of Westminster, Gerald Cavendish Grosvenor was near the top of the list. He made most of his money from inherited land that dates back to 1677. He owned the Grosvenor family estate, which has 300 acres across west London, including in wealthy areas like Belgravia and Mayfair. His property-development pipeline was also at £5.5 billion ($7.92 billion) as of the end of 2015. However, in light of his death, his son Hugh Grosvenor (pictured) is set to inherit his estate.