Scientist Stephen Hawking died at the age of 76 in the early hours of Wednesday, said a spokesman for his family.
His family later released a statement confirming his death at his home in Cambridge.
"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. We will miss him forever," Hawking's children said in a statement.
He was best known for his work on black holes and his theory of relativity.
Hawking was born in Oxfordshire in 1942 and studied at the University of Oxford.
In 1963, he was diagnosed with motor neurone disease 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 wrote many books and won a string of awards throughout an illustrious career.