Renowned British physicist Stephen Hawking, whose mental genius and physical disability made him a household name and inspiration across the globe, has died at age 76, a family spokesman said Wednesday.

"We are deeply saddened that our beloved father passed away today," professor Hawking's children, Lucy, Robert, and Tim said in a statement carried by Britain's Press Association news agency.

"He was a great scientist and an extraordinary man whose work and legacy will live on for many years."

Hawking defied predictions he would only live for a few years after developing a form of motor neurone disease that left him confined to a wheelchair.

"His courage and persistence with his brilliance and humour inspired people across the world," the family said.

"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."