“He came. He saw. He went home.” So ran the tag-line of the Irish box office smash hit comedy I, Keano, an epic musical melodrama about a Roman legion preparing for war. It was inspired by a real-life melodrama of even more epic proportions: arguably the most fractious falling-out in the history of Irish sport, a gripping and often amusing controversy prompted by Roy Keane’s contentious departure from the Republic of Ireland World Cup squad in 2002.

The captain’s headline-grabbing exit from the squad briefly transformed the tiny western Pacific island of Saipan into the most famous places on Earth. It made a cute and goofy Labrador puppy named Triggs into a household name. It was the source of more pompous pontification in the bars of the British Isles than any number of budgets, general elections and scandals. It practically sundered a nation, driving it to the brink of something approaching civil war and prompted the Taoiseach (prime minister) of the day to offer his services as a mediator. It became the subject of more hand-wringing sanctimony and general tomfoolery than almost any incident before or since in modern Irish life. It was all about standards. Roy’s standards. Depending on your point of view they were either too high or not high enough. Was Roy the perfectionist who wanted the best for his country or the traitor who abandoned it? In Ireland, 16 years on, the jury remains out.

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Everybody and nobody seems to know exactly what happened. The definitive version remains unconfirmed and even now, those who were privy to events as they unravelled remain understandably reluctant to talk about them in too much depth. Keane’s detractors claim he walked. His supporters insist he was sent home. The truth seems to lie somewhere in between: he made his position untenable and forced his manager’s hand.

This much we know: Ireland’s captain, then a 30-year-old volatile driving force who had almost single-handedly dragged his country through qualification for Japan and South Korea 2002 out of a group containing Portugal and Holland, decided to leave the camp out of frustration at poor preparation but then changed his mind. However, a newspaper interview he’d given to the Irish Times rolled off the presses like a grenade and exploded, prompting the famous showdown at which Keane embarked on a character assassination of his manager, Mick McCarthy, that was so brutal, the object of his scorn felt compelled to say he could no longer work with his captain.

In a chat with me for the Irish magazine Hot Press a few months after the event, the former Republic of Ireland international Niall Quinn insisted that “Roy walked out”. Later in the same interview he stressed that Keane had walked out “twice in three days”. He could not have been more clear: “You must remember that,” he said. “We’re not talking about a happy bunny here, who suddenly said the wrong things for a few seconds. I think it built up and up in him. While the rest of us were prepared to get on with things, knowing how ramshackle things are, he allowed it to get in the way of his World Cup.”

Roy Keane was the only subject that mattered in Ireland in the summer of 2002.

Keane tells it differently, stating in his autobiography that having originally become so exasperated by a rock-hard training pitch, the FAI’s failure to get their squad’s training kit to Saipan and a row about five-a-side goalkeeping arrangements, he decided to throw his hat at the whole jamboree and go home. A short time later, having been given time to cool down and review his position, he subsequently changed his mind only to be, in his opinion, ambushed at a team meeting called by McCarthy, who accused him of having faked an injury to avoid having to play the second leg of Ireland’s successful qualifying play-off against Iran. That, according to Keane, was the straw that broke the camel’s back and the cue for his outburst, which Quinn described as “the most surgical slaughtering anyone has ever got”.

“You’re a fucking wanker. I didn’t rate you as a player, I don’t rate you as a manager and I don’t rate you as a person. You’re a fucking wanker and you can stick your World Cup up your arse. I’ve got no respect for you. The only reason I have any dealings with you is that somehow you are the manager of my country! You can stick it up your bollocks.”

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“Humiliation in front of the whole party was the result he was seeking,” wrote Keane of McCarthy in his autobiography, stating that the meeting had been a set-up. Not too long after that, Keane received a phone call from his representative, the Irish solicitor Michael Kennedy. “You’ve been kicked out,” he was told. At 6pm the next day, with the rest of the Republic of Ireland squad en route to Japan, Keane was on the next plane home. How had it come to this?

Since his days as a youth footballer making a name for himself in Cork, Keane had never had much time for the FAI, an organisation that favoured players from Dublin clubs to those from elsewhere in the country. Upon becoming a senior international, he was increasingly perplexed by its amateurish approach to match preparation and was not alone, as a cursory flick through the autobiographies of any Republic of Ireland international who played through the Jack Charlton and Mick McCarthy eras will prove.

Roy Keane speaks to reporters before leaving Saipan on a flight home.

Things began to go pear-shaped at the airport on the way to Saipan. Already annoyed that he had been criticised in some newspapers for missing Quinn’s famously generous fundraising testimonial in Sunderland in favour of remaining in Manchester for treatment on a number of injuries that were threatening to rule him out of the World Cup, Keane was in understandably grumpy mood at Dublin airport and immediately buttonholed a couple of the journalists who had portrayed his non-attendance as a “snub”. The journey to Saipan had started badly and went quickly downhill. “The trip is a shambles from the beginning,” recalls Keane in his book. “Dublin airport is packed, you can’t move. We hump a month’s luggage through the main concourse. Check ourselves in. We’re travelling KLM, going the scenic route, via Amsterdam and Tokyo. Fans, journalists, players, officials all mingle together. The package tour image comes to mind again. Amid the chaos, the Taoiseach, Bertie Ahern, arrives to give us a send-off.”

With Keane already seething, it was left to Hollywood actor Will Smith to make things worse. On the flight to Tokyo, Ireland’s captain killed time watching Smith’s portrayal of Muhammad Ali and was transfixed by the scene in which the boxer resists the urgings of his family, friends and advisers to accept the draft for the Vietnam war. “They’re all urging him to give in,” recalls Keane. “Take the draft. You won’t have to fight. Just go through the motions, play the game, screw the things you believe in. Ali resists them all. I’m doing what I think is right. It matters. You don’t compromise on your principles. Watching this is very moving. I hadn’t known this about Ali. Something in this scene strikes a chord with me. Don’t put up with shit. I’m not fighting a white man’s war. It’s an inspiring notion, a demonstration of conviction that I understand very clearly and I relate to my own life. Don’t compromise the things you believe in.”

Nice one, Will.

Emboldened by what he had seen on his flight to Tokyo, Keane was unimpressed when Ireland’s squad eventually arrived in Saipan for what was ostensibly a week of pre-World Cup relaxation with some light training, only to discover their hampers of training kit, footballs and medical supplies had not arrived on the island. It was his nightmare scenario: Ireland preparing for a tournament in what he described as “happy-camper mode with no real ambition, settling for second best”. Visiting McCarthy in his hotel room, he voiced his disquiet and told his manager the team’s gear should have arrived the previous week. The following morning, Monday, Ireland’s players arrived at their training ground for a run to discover the surface was too hard. “We could have watered it,” Fifa’s liaison officer told Keane. “If anyone had told us you were coming down.” Fail to prepare, prepare to fail.

Roy Keane keeps busy by walking his dog Triggs.

Things went from bad to worse. The missing equipment arrived that night and the following day the squad had a full training session on a pitch that was still too hard, apart from one section, which had been flooded by those responsible for watering the pitch. When the training session finished with a game, Keane was outraged to discover the squad’s goalkeepers were unwilling to play on the grounds that they were too tired, having begun training half an hour before everyone else. In front of a couple of journalists, he got in a heated argument with the reserve goalkeeper Alan Kelly, one of the players in the squad he rubbed along with better than most. With Lee Carsley and Steve Finnan having picked up injuries on the training pitch, Keane decided he’d had enough of Ireland’s “third world approach to the game” and upon returning to the team hotel, he took McCarthy to one side and announced he wanted to go home.

The way Keane tells it, he subsequently apologised to Kelly for the row they’d had, went for a walk and was persuaded to stay on by team physio, concierge and agony uncle Mick Byrne. Upon being informed of the U-turn, McCarthy told Keane he’d already asked the Celtic midfielder Colin Healy to come out as his replacement. Feeling bad for Healy, Keane left it up to McCarthy to decide what should happen next. “I was indecisive,” recalls Keane. “I desperately wanted to play. Yet I couldn’t stand the fuck-ups. There is no hero here.” The indecision continued: Keane told Byrne he was definitely going, secretly hoping he’d be invited to stay. With the news of his imminent departure breaking in Ireland, he spoke on the phone to his adviser Kennedy, then Alex Ferguson. His Manchester United manager told him he had earned the right to change his mind and remain in Saipan. With mere minutes to go before the Republic of Ireland were due to fax their World Cup squad to Fifa, Keane decided to stay and a potential crisis appeared to have been nipped in the bud. Determined to keep his head down and his mouth shut until the squad moved to their proper training camp on the mainland, Keane did exactly that … apart from honouring promises to give a couple of interviews to favoured journalists, one of which appeared in the Irish Times the day before the Irish squad were due to leave the island. What could possibly go wrong?

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“It expressed exactly what I felt,” said Keane of the interview in his book. “I believed the people at home had a right to know the truth. The Irish fans are celebrated for the support they give the team. Thousands of them were flying out on expensive packages to support us in the World Cup. My own brothers and cousin were coming. It was the trip of a lifetime for them. Millions more would be watching the matches at home, as I’d done in 1988 and 1990. Were the people to be treated like mugs? They spent their hard-earned money, paid our wages and then we insult them with PR crap about all they’ve done for us. Maybe we should do something for them to repay the debt we owed them. Like get our act together. And tell them the score now and then.”

The end was nigh. The interview caused a sensation in both Ireland and Saipan, prompting the team meeting which resulted in Keane’s exile from the squad. At a hastily convened press conference, McCarthy confirmed the news of Keane’s departure flanked by his new captain Steve Staunton, along with Kelly and Quinn in a show of solidarity. Upstairs in his room, Keane bade farewell to a procession of largely sympathetic team-mates at the door of his hotel room. His World Cup jig was very much up.

Months later, Quinn expressed his regret at the manner in which events had unfolded. “When Roy exploded like he did, we needed to have a 24-hour cooling off period,” he told me. “Looking back, I think the events of history would have been a lot different if we had done that. Roy walked out, Mick called a press conference and it seems like minutes later myself, Stan and Alan Kelly are in there with Stan [Steve Staunton] as the new captain. Obviously, at the time we were shocked by what Roy had done, but Mick had asked us to stick up for him because he knew there’d be a hostile reception waiting for him. We knew we were putting ourselves in a dreadful position but we walked in with no other choice at the time. There was no way Roy was going to walk in and apologise a minute later, it was too intense for that. But at the same time, we might have prepared ourselves and structured ourselves for what was going to happen a little bit better. After that, I could give you a list of 20 other mistakes we made, all horrendous stuff. I’m almost apologetic for the mistakes we made. I’m certainly apologetic for the mistakes I made.”

Facebook Twitter Pinterest Roy Keane, photographed for the Guardian in 2002. Photograph: Murdo Macleod/The Guardian

Appearing at the press conference alongside McCarthy, Kelly and Staunton appears to have been Quinn’s biggest mistake, as Keane saw it as an outright act of betrayal. Wounded at having been accused of disloyalty by McCarthy for feigning injury, he was outraged that none of his team-mates, particularly the more senior ones for whom Japan and South Korea represented a last international hurrah, had not spoken out on his behalf when McCarthy rounded on him. Having made his own travel arrangements with help from staff at Manchester United, he went home to a house under siege from reporters. Several daily dog-walks with Triggs around Cheshire later, with Ireland’s World Cup opener against Cameroon looming, he granted an interview to RTE news reporter Tommie Gorman, who spoke of Keane’s role model status, all but berated him for his use of industrial language at a private team meeting attended by grown men, pleaded with him to think of Ireland’s children and urged him to reconsider his position. With the Irish football press pack listening in from Japan, courtesy of one of their relatives holding a phone up against a television in Dublin, the entire fiasco had officially entered the realms of high farce.

“If for one second I thought ‘Maybe Roy, you were a little bit out of order, maybe there’s a way back’, I’d be back on that flight,” said Keane to Gorman. “No doubts in my mind about that. But I went to my room and we had three players in a press conference within 20 minutes or half an hour of [the team meeting] saying they were behind Mick. People look at them as role models; they’re cowards. If I went back I couldn’t give 100% for my country. When they had their chance to speak up they didn’t.” Clearly bemused by a decidedly melodramatic interrogatory style in which Gorman pointed out that people in Ireland would be “absolutely haunted” by his departure from the squad, Keane was typically blunt. “That’ll pass,” he said. “People will get on with their lives. It’s a football tournament.” He was spot on. It did pass and most people did get on with their lives, but at the time in Ireland, such steely-eyed pragmatism went strangely unappreciated.