The 6th Duke of Westminster and former Grosvenor chairman had become ill and died on Tuesday afternoon at Preston Royal Infirmary.

One of Britain’s wealthiest landowners, Forbes estimated his net worth at $10.8bn (£8.3bn), making him the 68th wealthiest person in the world. 

Land owned by the Grosvenor chairman and former army general included more than 70 ha in Belgravia and dozens of hectares of land across the UK and in Spain, Forbes said.

A statement posted on Grosvenor’s website read: “It is with the greatest sadness that we can confirm that the Duke of Westminster, Gerald Cavendish Grosvenor (64) died this afternoon at Preston Royal Infirmary.  He was taken there from the Abbeystead Estate in Lancashire where he had suddenly been taken ill.

“His family are all aware and they ask for privacy and understanding at this very difficult time.”

Grosvenor said further information would follow in due course.

A Buckingham Palace spokeswoman was reported as saying: “I can confirm that Her Majesty the Queen is aware of the news about the Duke of Westminster. A message of condolence is being sent by the Queen and the Duke of Edinburgh.”

He is survived by his wife Natalia and four children.