My crazy, hazy days with the late, great godfather of Gonzo

Ralph Steadman tells for the first time how a meeting with a former Hell's Angel changed the face of journalism. By Martin Hodgson and Katy Guest

When a little-known Welsh cartoonist met an ex-Hell's Angel in a US bar more than three decades ago, the result was electric. "A voice like no other cut into my thoughts and sunk its teeth into my brain," recalls the British artist. "It was a cross between a slurred karate chop and gritty molasses."

The meeting spawned the birth of Gonzo journalism as Ralph Steadman, who had travelled to America after giving up his ambition of being a banker, struck up a drink- and drug-fuelled relationship with Hunter S Thompson, author of iconic books such as Fear and Loathing in Las Vegas.

Now, for the first time, Steadman has given his account of the relationship between the pair, who shocked the world with their dark, drug-crazed stories of life, politics and arts in 1970s America.

Steadman reveals that he has written a memoir "as a form of therapy" after Thompson shot himself last February. "When he died it was as though a piece of shoreline had split off and fallen into the sea. I had to write myself out of the emptiness," he said.

Thompson was 67 when he turned his gun on himself at his isolated Colorado ranch, but the manner of his death was no surprise to Steadman. Confined to a wheelchair by a spinal operation and hip replacement, Thompson had often spoken of suicide, but, Steadman reveals, what pushed him over the edge was the result of the US presidential elections in November 2003.

A maverick who spent much of his life railing against the corruption of mainstream politics, Thompson had once ran unsuccessfully for office as the leader of the Freak Party. But in the last months of his life he had thrown his support behind John Kerry's campaign. "When George W Bush got back in, I think that was the straw that broke the camel's back," Steadman said.

The two men met in 1970, when they were commissioned by Scanlan's magazine to cover the Kentucky Derby together. At first, there seemed little common ground between the acerbic American writer and the diffident Welsh artist. "It was chalk and cheese. We were so different, but I intrigued him because I did such vicious drawings," Steadman recalled.

Despite their outward differences, Steadman and Thompson soon developed a symbiotic working relationship that was to change the face of journalism. They initially bonded over a mutual enthusiasm for alcohol: "The drawings told me everything. I was out of control. They were the scribblings of some raving drunk," said Steadman.

Similarly incapacitated, Thompson was unable to finish his article. Instead, he ripped the unfinished pages from his notebook and filed them to his editors, setting the mould for a style of journalism in which the writer plunged head first into the scene he was reporting. "Gonzo was about becoming the eye - jumping straight into the first person," said Steadman.

When the two men first met, Steadman was best known for his work in Private Eye, and he credits Thompson with focusing the savage vision of his cartoons. "We changed each other's lives. After meeting him I realised that a drawing could be a weapon - and that I liked to use it," said Steadman.

"When I did pictures with Hunter I got butterflies in my stomach and it was very exciting. He made you realise how lazy and how respectable and how tired you'd become. He was an exhilarating person to be around."

In turn, Steadman gave Thompson an outsider's view of the absurdities of America. "He watched me watching the world. As a stranger in his country I was able to remind him of things he'd forgotten," he said.

Their best-known work, Fear and Loathing in Las Vegas, was made into a film starring Johnny Depp. But not all of their collaborations were so fruitful: a 1973 commission from Rolling Stone to cover the Ali-Foreman fight in Congo ended in chaos when Thompson sold their tickets to the fight to buy drugs, and the magazine's art director rejected Steadman's pictures.

"I regret the work we didn't do," said Steadman.

Steadman will next month publish his recollections of their unique friendship and creative collaboration. The Joke's Over is an intensely personal work.

The book is honest about Thompson's dark side: the mood swings and occasional bouts of drug-fuelled paranoia, but Steadman retains a deep affection for the man who once referred to him in print as a "scum-sucking foreign geek".

"You knew that he loved you if he took the time to insult you. He would insult you with such vitriol, but you'd think, 'The worse it gets, the more he loves me.'"

Thompson never fulfilled his dream of writing a truly great novel, and near the end of his life admitted he no longer even enjoyed writing. Steadman refutes the idea he wasted his talent. "He was probably a great writer, but a lot of his best stuff was his conversation and his life. He didn't squander his talent - he used it in an amazing way.

"I miss him a lot ... bawling at the end of the phone. It was the most difficult friendship in my life, yet probably one of the most essential."