Gerry Anderson, the creator of hit TV shows including Thunderbirds, Stingray and Joe 90, has died at the age of 83.
He also created Captain Scarlet and the Mysterons and his puppet superheroes fired the imaginations of millions of young viewers in the 1960s and '70s.
Thunderbirds, a science-fiction fantasy about a daring rescue squad, ran from 1965 and was his most famous show.
Anderson had suffered from Alzheimer's since 2010 and the disease had worsened in recent months, his son Jamie said.
Jamie Anderson announced the news on his website, saying his father died peacefully in his sleep at noon on Wednesday.
"Gerry was diagnosed with mixed dementia two years ago and his condition worsened quite dramatically over the past six months," he wrote.
Gerry Anderson talked about the onset of the disease in June 2012.
Speaking on BBC Berkshire he said: "I don't think I realised at all. It was my wife Mary who began to notice that I would do something quite daft like putting the kettle in the sink and waiting for it to boil."
His other creations included UFO, Space: 1999, Supercar and Fireball XL5.
Anderson said his favourite creation was Parker, Lady Penelope's butler and chauffeur in Thunderbirds.
Voice actor David Graham, who voiced the reformed safecracker, as well as fan-favourite Brains, said it was "a very sad day".
"I owed him a lot professionally and he was a good friend as well," he told the BBC. "I think he was a genius."
He revealed the inspiration for the voice came when Anderson "took me to an old pub in Cookham where there was an old guy who was a waiter and he said, 'I'm going to call him over, just listen to him'."
Actor Brian Blessed, who worked with Anderson on shows including The Day After Tomorrow and Space 1999, told BBC News: "I think a light has gone out in the universe.
"He had a great sense of humour. He wasn't childish but child-like and he had a tremendous love of the universe and astronomy and scientists.
"He got their latest theories, which he would expand on. He was always galvanised and full of energy."
Celebrities paying tribute on Twitter included comedian Eddie Izzard, who wrote: "What great creation Thunderbirds was, as it fuelled the imagination of a generation."
TV presenter Jonathan Ross wrote: "For men of my age, his work made childhood an incredible place to be."
Anderson, who lived in Henley-on-Thames, Oxfordshire, began his career studying fibrous plastering, but had to give it up when it gave him dermatitis.
After a spell in photographic portrait work, a job in Gainsborough films and time spent in air traffic control, he set up AP Films with some friends.
Commissions were few, however, so he responded eagerly to the opportunity to make a puppet series called The Adventures of Twizzle in 1956. It was nine years before Thunderbirds came into being on ITV.
The action was filmed on Slough Trading Estate in Berkshire.
The story revolved around International Rescue, a futuristic emergency service manned by the Tracy family, often assisted by Lady Penelope - voiced by Mrs Anderson - and her butler, Parker.
It included the catchphrases "Thunderbirds are go!" and "FAB".
The show marked the career apex for Gerry and his wife Sylvia, who had honed their "supermarionation" technique on Fireball XL5 and Stingray.
Nick Williams, chairman of Fanderson, the Gerry Anderson appreciation society, described him as "a quiet, unassuming but determined man".
"His desire to make the best films he could drove him and his talented teams to innovate, take risks, and do everything necessary to produce quite inspirational works," he said.
"Gerry's legacy is that he inspired so many people and continues to bring so much joy to so many millions of people around the world."