Che: the myth on your T-shirt: Twenty-five years after his death, Che Guevara proves that charisma can lead to quixotic deeds as well as to evil ones, says Jonathan Glancey

Che Guevara, 'the most complete human being of our age' according to Jean-Paul Sartre, was interrogated, then shot to death in a mud-walled schoolroom in the Bolivian village of Higuera on 9 October 1967.

Today this Latin American revolutionary is remembered as the poster that adorned student bedrooms around the world in the late Sixties and early Seventies. From Havana to Peking, via Washington, London, Paris and Berlin, Che was a symbol of youthful rebellion.

The myth of Che reached its zenith at the barricades in Paris in May 1968 when, for one brief moment, it looked as if Georges Pompidou's government might be toppled by stone-throwing students. Wherever students wrestled with police that year, Che marched with them, his image carried aloft like some religious icon. Within six months of his death, Che had been reborn as a slogan ('Che Lives]'), a poster, badge, T-shirt and, laughably, a boutique in Kensington High Street.

Che was, along with Mao's Little Red Book, the icon of radical chic and revolutionary posturing during that red summer of 1968.

At its most dangerous, the violence advocated by chic radicals led to groups of middle-class extremists like the Baader-Meinhof Gang in Germany, bent on vengeful destruction of the system that had allowed them to be destructive and vengeful. At its mildest, radical chic was no more than ludicrous posturing that had vanished in a cloud of embarrassing rhetoric within a year or two. Writers and poets across the world vied to write the most fulsome epitaphs. There is a photograph that shows Jean-Paul Sartre and Simone de Beauvoir in Havana listening intently to the battle- fatigued Che as he discusses the 'new man' and the politics of liberation. To Sartre, Che was Mathieu, the main character in his own trilogy The Roads to Freedom. Like Che, Mathieu, a middle-class intellectual, gives up rational argument in favour of a gun and fights for what he believes. In his moment of extremity he becomes Sartre's 'complete' man.

Just as embarrassing, although convincing at the time, was the Marxist art critic John Berger's analysis of the photograph of the dead Che surrounded by his captors in Bolivia. The picture had been wired to the world's press from La Paz on 9 October to prove that the Bolivian army - with a little help from the US military and the CIA - had indeed captured and killed the infamous Comandante Che Guevara. Berger likened this image to Andrea Mantegna's painting Dead Christ (although, more clinically, it also called to mind Rembrandt's Anatomy Lesson of Doctor Nicolaes Tulp). Che was more than a Marxist guerrilla; he personified the socialist Second Coming.

Graham Greene was typical of an older generation who fell for the myth of Che. His death, said Greene, was moving even to non-Marxists; Che, dead as alive, symbolised 'the individual in a state of permanent revolt'. Old-guard Communists in Moscow were moved by Che's death, too. The image of this latter-day Saint-Just made them feel guilty. For them the revolution had become far from 'permanent'; it was simply a word to be trotted out on anniversaries.

Oz magazine said Che, friend of youthful rebellion everywhere, was 'too serious to live into middle age'. But only just. When Che died he was 39 and a twice- married father of five.

The Che of the posters, T-shirts and slogans was whatever his admirers wanted him to be. To Africans he had black eyes and dark hair, to Russians chestnut hair and blue eyes. The Russians were right, but it hardly mattered. In Hollywood Che was Omar Sharif in Che], a film, according to Newsweek, without 'an ounce of political or historical sense'.

Even before his death, Che had passed into myth. In early 1965 he vanished on his return to Havana from a trip to Africa and Asia. There was speculation that he had fallen out with Castro. Paris Match reported his death. Some papers spotted him fighting with Francisco Camano's rebels in Santo Domingo; others reported him active in Peru, Vietnam and various parts of Africa. Adrian Henri wrote a song, The Amazing Adventures of Che Guevara, in which the bearded guerrilla popped up around the world like a Marxist jack-in-the-box. Che emerged in Bolivia in 1966, after six months fighting in the Congo. He survived just 11 months before his capture and execution by American-trained Bolivian troops. His mission to spread revolution throughout Latin America and the Third World, supported by Castro, had failed.

He won no support whatsoever from the local Indians he was supposedly fighting for and, because he, an Argentinian, refused to offer the leadership of the Bolivian revolution to Mario Monje, head of the national Communist party, he was isolated politically as well as militarily.

He was also a shadow of his poster-self. That essential dormitory poster was based on a photograph taken in 1959 when Che, freshly arrived in Havana after a three- year fight against the regular army of the Cuban dictator Batista, was 30. By the time of his execution nine years later, Che cut a different figure; suffering from malnutrition, rheumatoid arthritis and chronic asthma, he was at first hard to recognise.

This corpse was the real Ernesto Guevara de la Serna Lynch. He was born in Rosario, Argentina on 14 June 1928, the eldest son of Ernesto Guevara, of Spanish-Irish descent and Celia de la Serna, from a line of Spanish aristocrats. Che inherited their intellect and freewheeling politics. Crippled by asthma, he nevertheless became a formidable rugby player, an adventurous cyclist and a skilled skier and glider pilot. He studied medicine at Buenos Aires (graduating in 1953) and began to explore South America. His undoubted compassion for the sick and poor led him first to work in a leprosarium in Peru and then to fight for the survival of the left- wing Arbenz government in Guatemala (overthrown by Washington in 1954).

He was drawn into Marxist circles by his first wife, Hilda Gadea, a radical Peruvian socialist, and teamed up with Fidel and Raoul Castro in Mexico in 1955. By then Che had already been marked down by the CIA as a 'dangerous Communist revolutionary'.

Guevara was appointed doctor to Castro's invasion force and was nicknamed 'Che': like most Argentines he punctuated his sentences with the word, the equivalent of 'man', 'mac', 'buddy'. He fought heroically - there can be no doubt of that - and his column arrived in Havana in January 1959, the day after the Cuban dictator Fulgencio Batista fled and a week before Fidel Castro's triumphal entry. He executed enemies of the revolution and purged corruption with equal ruthlessness.

There is no doubt that Che quarrelled with Castro over the future of socialism in Cuba. Castro aligned himself, pragmatically, with Moscow. After the United States had cut off diplomatic and trade links, Moscow propped up the Cuban economy. Che, like Saint-Just before him, wanted to create a 'new man', who, caring nothing for money, would work for moral rather than purely financial incentives. There was no room for such idealism in Cuba in 1965. It was time for Che to go.

His last utterances from 'somewhere in the Third World' were disturbingly apocalyptic. He ended his last speech (relayed from the Bolivian jungle to the Tricontinental conference, Havana, April 1967) with words that were emblazoned on banners across the world the next summer: 'Wherever death may surprise us, let it be welcome, provided that this, our battle cry, may have reached some receptive ear and another hand be extended to wield our weapons and other men be ready to intone the funeral dirge with the staccato singing of machine guns and new battle cries of war and victory. Venceremos]' But within a few years, despite all the words spoken in the Argentinian's praise, only the poster remained.

Today, however, the Bolivian Indians who refused to support his struggle against the military regime of General Barrientos have remained loyal to the cult of the dead Che. They have the same photograph that John Berger commented on 25 years ago. It is the image of the Christ or at least a saint - San Ernesto de la Higuera - and one far removed from the dashing hero of the revolutionary poster. Nevertheless these two images of Che had at some point united two very different peoples: the stoic descendants of the Incas in Bolivia and the radical chic students of Paris, 1968.

Che failed. Yet otherwise sane family men followed him into the jungles of Cuba, the Congo and Bolivia to die; middle-class radicals placed his image over their beds to watch over them at night; peasants venerate a dead saint. Che does not live, but he shows us that in the 20th century political charisma has not only led to evil deeds on a mass scale, but also some remarkably quixotic ones.

(Photograph omitted)