The lion king of London

This film clip from 1971 has become an internet phenomenon, viewed by an estimated 50 million people worldwide. Yet the extraordinary footage of a loving reunion masks an even more extraordinary story. For five months in 1969 the two men, Australians Anthony "Ace" Bourke and John Rendall, lived with the lion, called Christian, in a flat on the King's Road, having bought him from Harrods for 250 guineas.

"It was Swinging London at that point," says Rendall, now a handsome sixtysomething. "People gravitated to Chelsea for the music, the fashion."

The dapper Bourke takes up the story: "Germaine Greer was writing The Female Eunuch in a [nearby] flat downstairs from Martin Sharp, who designed album covers for Bob Dylan, Cream and Jimi Hendrix; Eric Clapton was in a studio next door at The Pheasantry."

The two men worked in a pine furniture shop, Sophisticat, in World's End, close to Nigel Weymouth's boutique Granny Takes a Trip and Vivienne Westwood's first store. On a trip to Harrods' (now long-defunct) Zoo they were appalled to see two three-month-old lion cubs, a brother and sister, in a small cage. "It wouldn't be allowed now because of the 1976 Endangered Species Act, which we fully support," says Bourke. "But at the time it seemed like an adventure to buy a lion and we thought, perhaps naively, that we could care better for him." Rendall chips in: "The idea of a lion in the King's Road wasn't that unusual at the time. There was a serval cat living at World's End. Friends had a puma in Battersea. John Aspinall had tigers in his zoo and would sometimes bring them to London."

They bought the gentler male lion, called him Christian, and moved him into the sub-basement of Sophisticat. "When he was young he could just wander round the shop," says Bourke, "and there was a private walled park, the Moravian garden, just up the road, where we exercised him."

Christian proved boisterous, affectionate and playful and became a local celebrity. "A pregnant Mia Farrow came in and played with Christian," says Rendall. "She wasn't at all scared. Nor was Diana Rigg, but, hey, she's an Avenger!"

Unfortunately, their fellow Australian, 007 star George Lazenby, was too scared to come into the shop when he spotted Christian in the window. "I know, big butch George," sniffs Rendall.

Ironically, the lion prevented them from sampling too much of Sixties London, since he took up all of their time. "We didn't take him to parties," says Rendall. "Christian was the party." The lion didn't like new places - a visit to Kensington Gardens was "a disaster" - and they didn't want to exploit him. He starred in one Vanity Fair fashion spread, a promotional Christmas shoot with six newborn chicks (none was harmed) and a newspaper stunt when he opened an account at the King's Road NatWest. "That was to help with our overdrafts," says Rendall, wrily.

It cost £30 a week (£350 now) just to feed Christian and he was getting bigger and more powerful. Bourke and Rendall had always known they couldn't keep him for ever but felt he wouldn't be happy in a zoo or at Longleat safari park. Then, by chance, actors Virginia McKenna and her husband Ben Travers visited Sophisticat one day. They had played conservationists Joy and George Adamson in Born Free, the film about a lion, Elsa, who was returned to the wild. With the two Australians' enthusiastic approval, McKenna asked George Adamson if he could do the same for Christian.

In August 1970, Rendall and Bourke flew with Christian to Adamson's Kora nature reserve in Kenya, where he was gradually introduced to the wild. Despite his swanky Chelsea upbringing, he adapted well, eventually severing all ties with Adamson and Kora, mating with wild lions and disappearing to establish his own territory. In the YouTube footage from 1971 he is caught in a halfway stage, already comfortable with other lions but delighted that his old human friends have come to visit. "People assume we were scared but we could see the love and affection in Christian's face," says Bourke of their ecstatic reunion.

The massive online popularity of the clip has taken the men agreeably by surprise and led them to revise and reissue their excellent 1971 book, A Lion Called Christian. Owning Christian left both of them with an interest in conservation, Rendall professionally and Bourke as a sideline to his career as an art curator. Rendall hopes those viewing the clip will be prompted to take a greater interest in the world's ecological balance. "The number of lions today is a third of what it was when we bought Christian," he says. "That alone tells you something's wrong."

A Lion Called Christian is published by Bantam Press, £12.99.

To contribute to the George Adamson Wildlife Preservation Trust, go to www.georgeadamson.org