Nearly every James Bond actor has shared a secret. At some point during filming they have been introduced to a man called Powell. And each time that man has made sure that 007 drives faster, fights better and shoots straighter.

The Powell family is among the best-kept secrets in film, having performed Bond’s stunts for more than 40 years. In 20 films, Fred “Nosher” Powell, 80, and Dennis “Dinny” Powell, 76, or Nosher’s sons Greg, 54, and Gary, 45, have helped successive Bonds from Sean Connery to Daniel Craig do the dirty business of making Bond look good.

Remember when Pierce Brosnan barrel-rolled a speedboat on the Thames in The World Is Not Enough? That was Gary. Connery knocking seven bells out of opponents in From Russia with Love? That was Dinny, lending a helping hand. Any time Roger Moore fired his Walther PPK? That was Nosher or Dinny (Moore didn’t like the noise). Oh and the opening car chase in Quantum of Solace? Gary was behind that and is the only man who can claim to have trashed seven Aston Martin DBSs in the course of a fortnight.

It was Dinny who started what would become a family firm. He’d been going to the old Denham film studios in Buckinghamshire since his teens, earning £3 a day as an aspiring stuntman. His first Bond film was From Russia with Love, starring Connery — “a fit boy, a good swimmer and very straightfoward” — the second in the franchise.

There were no end-of-film credits for stuntmen — most film companies preferred to cover up their existence — but the action still had to be delivered. “You had to be prepared to take the knocks and Connery appreciated that,” says Dinny. “He was prepared to do a lot of the work, but there was no point in the film company taking risks. Without him, there would have been no film.”

Dinny then introduced his elder brother, Nosher, a former boxer, to the stunt team. And in the same way that circus families pass on their skills to the next generation, Nosher’s sons were soon co-opted into the family profession. “I bunked off school and served tea to the stunt guys,” recalls Gary of his time on the set of The Spy Who Loved Me in 1977. “I would collect all the machineguns at the end of the night from the guys and take them back to the armourer and he would let me fire off all the bullets. Can you imagine what a thrill that was for a 13-year-old schoolkid? I was hooked.”

Dinny and Nosher have stood in for Connery and Moore; Greg worked with Moore and then with Timothy Dalton; and Gary has worked with Brosnan and Craig. The only Bond the family didn’t work with was George Lazenby, who starred in On Her Majesty’s Secret Service in 1969. “He was good,” says Dinny. “But he had an ego problem.”

Moore, by contrast, was “a south London boy and a gentleman”, although he’d never have cut it as 007 without Nosher and Dinny’s loyal assistance. “He had the sense never to go near guns, so we did his shooting for him,” reveals Dinny. “He didn’t like them banging off — and he was right.”

Nosher has lost much of his hearing as a result, and Dinny’s is badly impaired. Dinny has broken his leg and his collarbone, and had to have a hip replaced after being rolled over by a horse. And they are just the headline injuries amid the daily cuts, bruises, sprains and strains. “That’s the nature of the game and you just accept it,” he says.

The next generation has had an easier run. “We have modern equipment which protects us,” says Gary. “When you see a Buster Keaton film, the stuntman was really hanging off a cliff, with no safety cables.”

Gary’s most dangerous stunt was posing as Brosnan and barrel-rolling that speedboat. “If the boat had come down at the wrong angle, it would have taken my head off,” he says.

The car chase that opens Quantum of Solace, with Craig apparently behind the wheel of a DBS (in fact two stunt drivers), proved that stunt work still carries huge risks. The action took place on winding mountain roads and tunnels in northern Italy. A driver was injured and a car fell into Lake Garda. “The stuntman has made a recovery, thank goodness,” says Gary. “The cars, though, were beyond repair.” Total cost about £1.2m.