Prince William has taken over a £345 million property portfolio from the King - and will become his father's landlord as a result.
The Prince of Wales will net around £700,000 a year from King Charles III after the Duchy of Cornwall was passed down.
The Duchy is given to the eldest son of a reigning British monarch and owns around 130,000 acres of land - including the King's beloved Highgrove home.
However, the Prince is not entitled to sell any of the Duchy's assets for personal benefit.
He will, however, collect hundreds of thousands of pounds of rent from his father, who has a long lease on Highgrove House which was purchased by the Duchy in 1980.
The Sun reports that the Duchy netted a £21million income last year.
Highgrove, in Gloucestershire, has been transformed by the King into a family home, while he also helped design the Cotswold property's gardens which attract 30,000 visitors a year.
Prince William's new property portfolio includes most of the Scilly Isles, HMP Dartmoor and the Oval cricket ground in south London.
A source told The Sun: “The King has a long lease and pays rent on Highgrove House and surrounding land.”
The house is reportedly the King's favourite and is close to Queen Consort Camilla's private property in Wiltshire.
The King gave up his Duchy Original farm at Highgrove last year in preparation for his ascension to the throne, declining a 20-year lease at the 900-acre Home Farm from where food boxes now sold at Waitrose were launched.
Charles is expected to reduce the living quarters at Buckingham Palace rather than live there full time, with a 10-year, £369 million renovation currently taking place.
In 2017, Charles took over the running of Sandringham in Norfolk and made big changes in a bid to make it fully organic.
Changes on the huge estate include creating wildlife corridors, installing bird boxes, and using organic fertiliser, while the King is rumoured to be keen to set up the country's biggest organic sheep farm there.
He also owns properties in Scotland, Wales and Romania.
