The Duke of Devonshire is the wealthiest individual in Derbyshire, according to the Sunday Times Rich List.
His wealth has increased from £720million last year to £800m this year, making him the 125th richest person in the country.
The Duke’s Chatsworth estate employs hundreds of people and attracts thousands of tourists from around the world – bringing millions of pounds into the local economy every year.
He succeeded to the dukedom following the death of his father in 2004.
With a net worth of £300m, John Kirkland, of Heage-based construction group Bowmer and Kirkland, is ranked 307th in the annual guide.
Established in 1923, Bowmer and Kirkland is one of the UK’s most successful privately-owned construction, engineering and development companies.
Meanwhile, north east tycoon Mike Ashley, the founder of Sports Direct, is worth a staggering £3.75billion, making him the 25th wealthiest individual in the UK.
The company employs more than 5,000 people at its headquarters on Brook Park, Shirebrook, with most controversially on either casual or zero-hour contracts.
The Sunday Times has been compiling its Rich List since 1989.
Tycoons the Hinduja brothers, of the Hinduja Group, a multinational conglomerate with a presence in almost 40 countries with businesses as diverse as trucks and lubricants to baking and healthcare, are top of the guide with a joint fortune of £11.9bn.
Philip Beresford, who compiles the Sunday Times Rich List, said: “The richest people in Britain have had an astonishing year.
“While some may criticise them, many of these people are at the heart of the economy and their success brings more jobs and more wealth for the country.”