Reykjavik, Iceland -- Bobby Fischer, the reclusive chess genius who became a Cold War icon by dethroning the Soviet Union's Boris Spassky as world champion in 1972, has died, his spokesman said Friday. He was 64.
Fischer spokesman Gardar Sverrisson said Fischer died in a Reykjavik hospital on Thursday. Icelandic media reported that he died of kidney failure after a long illness.
U.S.-born Fischer, a fierce critic of his homeland who renounced his U.S. citizenship, moved to Iceland in 2005.
Born in Chicago and reared in Brooklyn, N.Y., Fischer was wanted in the United States for playing a 1992 rematch against Spassky in Yugoslavia in defiance of international sanctions.
Russian former world chess champion Garry Kasparov said Friday that Fischer's ascent of the chess world in the 1960s was "a revolutionary breakthrough" for the game.
"The tragedy is that he left this world too early, and his extravagant life and scandalous statements did not contribute to the popularity of chess," Kasparov told The Associated Press.
Rival and friend Spassky, reached in France where he lives, said in a brief phone call that he was "very sorry" to hear of Fischer's death.
Kirsan Ilyumzhinov, president of the World Chess Federation, called Fischer "a phenomenon and an epoch in chess history, and an intellectual giant I would rank next to (Isaac) Newton and (Albert) Einstein."
An American chess champion at 14 and a grand master at 15, Fischer vanquished the Soviet Union's Spassky in 1972 in a series of games in Iceland's capital, Reykjavik, to become the first officially recognized world champion born in the United States. Paul Morphy, an American, was regarded as the world's best player from 1858 to 1862, and William Steinetz, an Austrian immigrant to the United States, was an official champion from 1886 to 1894.
The match, at the height of the Cold War, took on mythic dimensions as a clash between the world's two superpowers.
But Fischer's reputation as a genius of chess soon was eclipsed, in the eyes of many, by his idiosyncrasies.
He lost his world title in 1975 after refusing to defend it against Anatoly Karpov. He dropped out of competitive chess and largely out of view, emerging occasionally to make erratic and often anti-Semitic comments.
He resurfaced to play the exhibition rematch against Spassky on the resort island of Sveti Stefan. Fischer won, but the game was played in violation of U.S. sanctions imposed to punish Slobodan Milosevic, then president of Yugoslavia.
In July 2004, Fischer was arrested at Japan's Narita airport for traveling on a revoked U.S. passport and was threatened with extradition to the United States. He spent nine months in custody before the dispute was resolved when Iceland -- a chess-mad nation and site of his greatest triumph -- granted him citizenship.
In his final years, Fischer railed against the chess establishment, alleging that the outcomes of many top-level chess matches were decided in advance.
Instead, he championed his concept of random chess, in which pieces are shuffled at the beginning of each match in a bid to reinvigorate the game.
"I don't play the old chess," he told reporters when he arrived in Iceland in 2005. "But obviously if I did, I would be the best."
Born in Chicago on March 9, 1943, Robert James Fischer was a child prodigy, playing competitively from the age of 8.
At 13, he became the youngest player to win the United States Junior Championship. At 14, he won the United States Open Championship for the first of eight times.
At 15, he gained the title of international grand master, the youngest person to hold the title.
Tall and striking-looking, he was a chess star -- but already gaining a reputation for volatile behavior.
He turned up late for tournaments, walked out of matches, refused to play unless the lighting suited him and was intolerant of photographers and cartoonists. He was convinced of his own superiority and called the Soviets "Commie cheats."
His behavior often unsettled opponents -- to Fischer's advantage.
This was seen most famously in the showdown with Spassky in Reykjavik between July and September 1972. Having agreed to play Spassky in Yugoslavia, Fischer raised one objection after another to the arrangements and they wound up playing in Iceland.
When play got under way, days late, Fischer lost the first game with an elementary blunder after discovering that television cameras he had reluctantly accepted were not unseen and unheard, but right behind the players' chairs.
He boycotted the second game and the referee awarded the point to Spassky, putting the Russian ahead 2-0.
But then Spassky agreed to Fischer's demand that the games be played in a back room away from cameras. Fischer went on to beat Spassky, 12.5 points to 8.5 points in 21 games.
Millions of Americans, gripped by the contest, rejoiced in the victory over their Cold War adversary.
In the recent book "White King and Red Queen," British author Daniel Johnson said the match was "an abstract antagonism on an abstract battleground using abstract weapons ... yet their struggle embraced all human life."
"In Spassky's submission to his fate and Fischer's fierce exultant triumph, the Cold War's denouement was already foreshadowed."
Funeral details were not immediately available. Fischer moved to Iceland with his longtime companion, Japanese chess player Miyoko Watai. She survives him.
Associated Press Writers Jill Lawless in London and Mansur Mirovalev in Moscow contributed to this report.
American Bobby Fischer pauses before the start of the fifth game in Sveti Stefan, Yugoslavia, in this Sept. 9, 1992 file photo
Chess legend Bobby Fischer carries flowers as he arrives in Reykjavik, Iceland on Thursday, March 24 2005. Fischer accepted an offer of citizenship from Iceland, a country still grateful for it's role as the site of his most famous match.