19. John Fredriksen and family
Net worth: £6.703 billion
Sources of wealth: shipping and oil services
Fredriksen, 74, is also Norway's richest man. His fortune is largely down to what happened during the Iran and Iraq war of 1980 to 1988. His tankers managed to defy the fighting and pick up oil from the regions.
He also invests in shipping, fish-farming, and other oil-support operations.
18. Mohamed Bin Issa Al Jaber and family
Net worth: £6.747 billion
Sources of wealth: hotels, food and industry
Al Jaber runs the London-based MBI International Holding Group. It invests in property, hotels, food, and energy.
He is perhaps most famous for accusing Barclays of engaging in corrupt Saudi Arabian deals, which later led to Saudi Arabia claiming $10 billion in damages from the UK lender.
17. Andy Currie
Net worth: £7 billion
Source of wealth: chemicals
Cambridge University graduate Currie became director of chemicals giant Ineos 1998 having spent 15 years in various technical and managerial roles. The Sunday Times has seen financial documents suggesting Ineos made profits of up to £5.151bn last year under Currie's stewardship.
16. John Reece
Net worth: £7 billion
Source of wealth: chemicals
Working alongside Any Currie at Ineos is John Reece, the chemical company's finance director. Born in Sunderland, northeast England, Reece was a former PWC accountant before joining Ineos. The 61-year-old is credited with saving the company nearly £90 million a year.
15. Sir David and Sir Frederick Barclay
Net worth: £7.4 billion
Sources of wealth: property, media and internet retailing
The London-born twins made most of their money from retail and hotel operations, such as Maybourne, which is the owner of iconic London hotels Claridge's, the Berkeley, and the Connaught.
In 2015, they sold their stake in his group, which cost the Qatari purchasers £2.4 billion. The Sunday Times said they are "considering offloading a substantial stake in their £2 billion Shop Direct operation, which includes the brands Littlewoods and very.co.uk."
However, they are most famous for buying The Telegraph newspaper in 2004 for £665 million.
14. Hans Rausing and family
Net worth: £9.333 billion
Sources of wealth: packaging
Rausing and his wife's fortune is derived from his revolutionary packaging company Tetra Pak, which was later renamed to Tetra Laval.
The Rausing name has been in the spotlight in the last few years after the wife of his son, also called Hans, died in a drug overdose in 2012.
13. Roman Abramovich
Net worth: £9.333 billion
Sources of wealth: oil and industry
The insanely rich Russian oligarch made his money through a range of commodities and energy companies. His holdings in 13 businesses worth a combined £4 billion. He first sold the Sibneft oil operation to Gazprom for £7.5 billion in 2005, after buying it for only £120 million a decade earlier.
However, he is more famous in Britain for owning Chelsea Football Club, one of the top teams in the English Premier League.
He took a blow to his fortune when he divorced Irina Malandina but he is now married to Dasha Zhukova, 35.
12. Sir James Dyson and family
Net worth: £9.5 billion
Sources of wealth: household goods and technology
Industrial designer Dyson invented the bagless vacuum cleaner. His first ever invention was the Ballbarrow, a modified version of a wheelbarrow using a ball instead of a wheel, which he later implemented into some of his Dyson vacuum-cleaner designs.
11. Ernesto and Kirsty Bertarelli
Net worth: £9.659 billion
Sources of wealth: pharmaceuticals
Ernesto is Switzerland's richest man after he sold his family's pharmaceutical company Serono, which was Europe's biggest biotech firm at the time, to German drugmaker Merck in 2006 for £9 billion.
His combined wealth with his wife, Kirsty, the singer and model he married in 2000, makes her the richest woman in Britain. You can often spot them sailing around the world in the largest yacht ever built in the UK — the Vava II, which cost Ernesto £100 million and was built for Kirsty's 40th birthday.
10. The Duke of Westminster and the Grosvenor family
Net worth: £9.964 billion
Sources of wealth: property
Hugh Grosvenor became the Seventh Duke of Westminster after his father Gerald Cavendish Grosvenor died in August 2016.
The family makes most of their money from inherited land that dates back to 1677. The Grosvenor family estate, which has 300 acres across west London, including in wealthy areas like Belgravia and Mayfair.
9. Guy, George and Galen Jr Weston and family
Net worth: £10.05 billion
Sources of wealth: retailing
Galen was born in Buckinghamshire and derives most of his fortune from the huge George Weston operation in Canada. The group owns a number of huge food stores including Loblaw supermarket chain, Weston Foods, and the British branch of the Weston empire, Associated British Foods. It is run by his nephew, George, and bargain fashion retailer Primark.
8. Alisher Usmanov
Net worth: £10.556 billion
Sources of wealth: mining and investment
The Russian oligarch made his money through steel and iron-ore mines and companies such as Metalloinvest, and has a 30% stake in Arsenal Football Club. He has, however, started to move the ownership of some businesses back to Russia after President Vladimir Putin installed more favourable tax laws. He also grew rich through shares in Spotify and Airbnb.
7. Kirsten and Jorn Rausing
Net worth: £10.848 billion
Sources of wealth: inheritance and investment
The Swedish brother and sister, who are the leading shareholders of Swiss packaging group Tetra Laval (formerly known as Tetra Pak), live in Britain. Their father was Gad Rausing, who with his brother, Hans, initially inherited Tetra Pak. Jorn initially had a £26.5 million stake in the online retailer Ocado.
6. Charlene de Carvalho-Heineken and Michel de Carvalho
Net worth: £11.1 billion
Sources of wealth: inheritance, brewing and banking
Charlene de Carvalho-Heineken, pictured here, inherited Dutch brewer Heineken, worth £36.7 billion, as the only child of Freddy Heineken, who died in 2002. She lives in London and Switzerland with her husband, Michel.
5. Lakshmi Mittal
Net worth: £14.667 billion
Sources of wealth: steel
The steel tycoon's fortune is up £1.483 billion on 2017 following a number of challenging years. In 2015, his fortune decreased as oil and commodities prices tanked over 12 months, and in previous years, his company lost £5.5 billion and stopped paying a dividend to investors.
4. David and Simon Reuben
Net worth: £15.096 billion
Sources of wealth: property and internet
The Mumbai-born brothers and British citizens make most of their money through lucrative property deals after initially investing in the Russian metals market. Returns from their lucrative properties — such as the Millbank Tower, the John Lewis Partnership HQ in Victoria, and shops in Sloane Street — were solid.
3. Sir Len Blavatnik
Net worth: £15.259 billion
Sources of wealth: investment, music and media
Blavatnik became a billionaire after the fall of Soviet communism. He built his wealth through the control of oil producer TNK, partner of BP.
When it was sold to Russia’s Rosneft in 2013, Blavatnik’s share was worth more than £4 billion. He also invests in aluminium producers and chemical companies, as well as the world's largest producer of polypropylene LyondellBasell.
In 2011, he bought Warner Music and then The Beatles' label, Parlophone.
2. Sri and Gopi Hinduja
Net worth: £20.644 billion
Sources of wealth: industry and finance
The Hinduja brothers — who were top of last year's Sunday Times rich list — racked up their sizeable wealth through property development, car manufacturing, and more recently, the old War Office in London's Whitehall for £300 million.
They are so rich that the wedding for one of the brother's sons cost £15 million.
1. Jim Ratcliffe
Net worth: £21.05 billion
Sources of wealth: chemicals
Ratcliffe's net worth has increased a whopping £15.3 billion since last year, making him the first ever British-born industrialist to top the list. Ratcliffe the archetypal rags-to-riches story. He grew up on the outskirts of Manchester, where he "he used to count the chimneys he could see from his parents’ council house. It inspired him to forge a career in industry," according to The Sunday Times.
He then founded and now runs one of the world’s biggest chemical companies Ineos. He also owns yachts and an impressive property portfolio, which includes a huge estate in remote northeast Iceland that he bought in December.
Speaking to The Sunday Times in an interview published today, Ratcliffe said he was staggered by the growth of his company.
"Completely," he said. “You should see a picture of the council house where I started out."
He added: "Look, these are extremely big numbers, but I’m 65 and I’ve been doing this for 25 years. With the exception of 2008, we’ve been successful every year. So you do kind of get used to it."