Scientist Stephen Hawking has died at the age of 76, a spokesman for his family has said.
Professor Hawking's children, Lucy, Robert and Tim said in a statement that he had died at his home in Cambridge in the early hours of Wednesday.
They said: "We are deeply saddened that our beloved father passed away today.
"He was a great scientist and an extraordinary man whose work and legacy will live on for many years.
"His courage and persistence with his brilliance and humour inspired people across the world.
"He once said, 'It would not be much of a universe if it wasn't home to the people you love.'
"We will miss him forever."
They asked for privacy but added their thanks to "everyone who has been by Professor Hawking's side and supported him - throughout his life".
The world famous physicist and cosmologist was the subject of the 2014 film The Theory Of Everything, which starred Eddie Redmayne and Felicity Jones.
He also performed several cameos in the US comedy series The Big Bang Theory.
Hawking contracted motor neurone disease in 1963 and was given two years to live but he went on to study at Cambridge and became one of the most brilliant theoretical physicists since Albert Einstein.
He was given more than a dozen honorary degrees and was awarded the CBE in 1982.
The University of Cambridge will open a book of condolence at Gonville and Caius College for anyone who would like to pay tribute to Hawking's life and work.