Mar 14 (BBC) Stephen Hawking has died at the age of 76, his family has said.
The British physicist was known for his work with black holes and relativity, and wrote several popular science books including A Brief History of Time.
"We are deeply saddened that our beloved father passed away today," a family statement said.
At the age of 22 Stephen Hawking was given only a few years to live after being diagnosed with a rare form of motor neurone disease.
His family said that he died peacefully in his home near Cambridge University, where he did much of his groundbreaking work on black holes.
In the statement his children, Lucy, Robert and Tim, said: "He was a great scientist and an extraordinary man whose work and legacy will live on for many years."
They praised his "courage and persistence" and said 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."
Prof Hawking was the first to set out a theory of cosmology as a union of relativity and quantum mechanics.
He also discovered that black holes leak energy and fade to nothing - a phenomenon that would later become known as Hawking radiation.
The scientist gained popularity outside the academic world and appeared in several TV shows including The Simpsons, Red Dwarf and The Big Bang Theory.