As Only Fools and Horses' smarmy businessman Boycie, John Challis played one of the most memorable characters in one of the most memorable British TV shows of all time - not to mention having one of the most memorable (if irritating) laughs.
Boycie was the sneeringly superior, shiny-suited, sharp-practising second-hand car salesman who liked to have a laugh - a long, nasal, grating laugh - at the expense of Del Boy and Rodney, but who often ended up being the butt of the joke himself.
Usually found in the Nag's Head with a cigar, a large cognac and his wife Marlene (or, rather, "Marrrrrleeeeene!"), he was an integral part of the appeal of the show that has been voted Britain's greatest sitcom and attracted 24 million viewers at its peak.
It was a role that earned John Challis a place in the British TV hall of fame, and with which he was forever associated - even if there was more to his career and his life story than just being Boycie.
Challis was born in 1942 in Bristol, with his father a civil servant in the Admiralty in nearby Bath. When the Admiralty moved to the capital, Challis was - as he later joked - "the only child who was evacuated to London during the war".
His acting career began in a travelling children's theatre company and then touring regional rep before he appeared in the West End and spent a year with the Royal Shakespeare Company in the mid-1960s.
He was originally cast in The Beatles' 1967 Magical Mystery Tour film after being interviewed by the band themselves.
"John Lennon was lying on the floor, Paul was behind a desk being efficient and running the whole thing, and Ringo was sitting on the arm of my chair gazing at me intently," Challis later recalled.
"John asked me what sort of music I liked. I answered truthfully, 'I like the Rolling Stones. I prefer their sort of music really'. There was a short pause and he said, 'Yeah, so do I'.
"As I left I heard him say, 'He's great, get him'."
However, to his regret, Challis was unable to play the part because it clashed with an early BBC soap opera titled The Newcomers, which gave him his breakthrough on the small screen, before he joined police drama Z Cars.
He also appeared in The Sweeney, Doctor Who - playing a ruthless mercenary called Scorby in six-part 1976 serial The Seeds of Doom - and had a small part opposite his future Only Fools and Horses co-star David Jason in Open All Hours.
Challis was performing in two Tom Stoppard plays in New York when his agent called to ask him to come home to film an episode of the comedy series Citizen Smith. "I was in two minds," he later said. "I'd been completely seduced by America and thought I might stay and become an international film star.
"As I'd run out of money I decided to take a chance, and getting on that plane to London was the moment that changed my life."
The Citizen Smith role was a cameo appearance as a corrupt police inspector. "I played a lot of cameo roles in a lot of series for a long time," he said. "I'd played an awful lot of policemen."
So he tried to find a different way to tackle this character - and ended up copying the pedantic voice of a know-it-all from his old local pub.
Citizen Smith's writer John Sullivan liked the performance so much that he created a role for Challis in his next show - Only Fools and Horses.
"He later said to me that I reminded him with that performance of someone he used to know in south London who was a second-hand car dealer," Challis explained.
But Boycie didn't have his trademark laugh at first. "One day in the back of my mind I remembered a cackly old woman I used to see around the place and she had this machine gun-like laugh," the actor told BBC Radio 5 Live in 2015.
"I just did it one day as a joke and everybody just fell about and said, 'Keep that in'. And then it got into the scripts - 'Boycie does one of his laughs' - as a stage direction. And I've been doing it ever since."
Challis was in his 40s by the time Only Fools and Horses - and Boycie - became national institutions in the 1980s.
The character's memorable moments included losing to Del Boy in a high-stakes card game, revealing his middle name was "Aubrey" during a seance, and inadvertently acting as a jailer to a kidnapped "asylum seeker" in the Trotters' Peckham flat.
But during that period, Challis's personal life was not going as well as his career. He wrote in his second autobiography that his third wife was having an affair, he had a destructive relationship with a woman he called the "Dangerous Dane", and he made a disastrous investment in a friend's aloe vera farm in Portugal.
"That was a pretty dark time," he said. "That is the irony that Boycie was doing terribly well, but John Challis was in a bit of a state."
He started drinking heavily, but credited his fourth wife Carol with halting his descent.
After Only Fools and Horses finished in 2003, Boycie and Marlene were given their own spin-off, The Green Green Grass, which ran from 2005 to 2009.
Challis also appeared in Last of the Summer Wine, played Captain Peacock in the 2016 revival of Are You Being Served?, and was in ITV's Benidorm from 2015-2018.
But with Only Fools and Horses still remembered fondly - and continually repeated on TV - he was forever associated with Boycie. While that could be a "double-edged sword" at times, he was proud to have played a big part in such a well-loved show.
"Whatever plays I've done or other work, it's Only Fools that people want to talk about," he said.
"But I'm quite happy. I know I've created someone that people will remember and smile about."