London (AFP) - British billionaire Gerald Cavendish Grosvenor, one of the world's richest people, died on Tuesday according to his estate.
The 64-year-old Duke of Westminster died at a hospital in Lancashire, north-west England, a spokeswoman for his estate said.
He had been taken there from his sprawling country estate Abbeystead where he had "suddenly been taken ill", she added, without giving further details of the illness.
"His family are all aware and they ask for privacy and understanding at this very difficult time."
Grosvenor and his family rank 68th in Forbes' rich list of global billionaires, with a net worth of $10.8 billion (£8.3 billion, 9.7 billion euros).
The British landowner owned 190 acres in Belgravia, an area adjacent to Buckingham Palace and one of London's most expensive boroughs.
He lost $1 billion in the immediate aftermath of Britain's vote in June to leave the European Union, which sent the value of the pound plummeting and shook the property market, according to Bloomberg.
The family also has ties to the British royal family as one of Grosvenor's four children, Hugh, is a godfather to Prince George, the three-year-old son of Prince William and his wife Kate.
Queen Elizabeth II and her husband Philip sent a message of condolence following news of Grosvenor's death, a Buckingham Palace spokeswoman said.