Kremlin spokesman Alexander Smirnov confirmed Yeltsin's death, but gave no cause or further information. The Interfax news agency cited an unidentified medical source as saying he had died of heart failure.

Although Yeltsin pushed Russia to embrace democracy and a market economy, many of its citizens will remember him mostly for presiding over the country's steep decline.

He was a contradictory figure, rocketing to popularity in the Communist era on pledges to fight corruption but proving unable, or unwilling, to prevent the looting of state industry as it moved into private hands during his nine years as Russia's first freely elected president.

He steadfastly defended freedom of the press, but was a master at manipulating the media.

He amassed as much power as possible in his office then gave it all up in a dramatic New Year's address at the end of 1999.

Yeltsin's greatest moments came in bursts. He stood atop a tank to resist an attempted coup in August 1991, and spearheaded the peaceful end of the Soviet state on Dec. 25 of that year. Ill with heart problems, and facing possible defeat by a Communist challenger in his 1996 re-election bid, he marshaled his energy and sprinted through the final weeks of the campaign. The challenge transformed the shaky convalescent into the spry, dancing candidate.

But Yeltsin was an inconsistent reformer who never took much interest in the mundane tasks of day-to-day government and nearly always blamed Russia's myriad problems on subordinates.

Yeltsin damaged his democratic credentials by using force to solve political disputes, though he claimed his actions were necessary to keep the country together.

He sent tanks and troops in October 1993 to flush armed, hard-line supporters out of a hostile Russian parliament after they had sparked violence in the streets of Moscow. And in December 1994, Yeltsin launched a war against separatists in the southern republic of Chechnya.

Tens of thousands of people were killed in the Chechnya conflict, and a defeated and humiliated Russian army withdrew at the end of 1996. The war solved nothing and Russian troops resumed fighting in the breakaway region in fall 1999.

In the final years of his leadership, Yeltsin was dogged by health problems and often seemed out of touch. He retreated regularly to his country residence outside Moscow and stayed away from the Kremlin for days, even weeks at a time. As the country lurched from crisis to crisis, its leader appeared increasingly absent.

Yet Yeltsin had made a stunning debut as Russian president. He introduced many basics of democracy, guaranteeing the rights to free speech, private property and multiparty elections, and opening the borders to trade and travel. Though full of bluster, he revealed more of his personal life and private doubts than any previous Russian leader had.

"The debilitating bouts of depression, the grave second thoughts, the insomnia and headaches in the middle of the night, the tears and despair ... the hurt from people close to me who did not support me at the last minute, who didn't hold up, who deceived me I have had to bear all of this," he wrote in his 1994 memoir, "The Struggle for Russia."

Yeltsin pushed through free-market reforms, creating a private sector and allowing foreign investment. In foreign policy, he assured independence for Russia's Soviet-era satellites, oversaw troop and arms reductions, and developed warm relations with Western leaders.

That was the democratic Yeltsin, who in August 1991 rallied tens of thousands of Russians to face down a hard-line Soviet coup attempt. Throughout his nearly decade-long leadership, he remained Russia's strongest bulwark against Communism.

But there was another Yeltsin.

He was hesitant to act against crime and corruption beginning in his own administration while they sapped public faith and stunted democracy. His government's wrenching economic reforms impoverished millions of Russians poor people whose wages and pensions Yeltsin's government often went months without paying.

In the course of the Yeltsin era, per capita income fell about 75 percent, and the nation's population fell by more than 2 million, due largely to the steep decline in public health.

Yeltsin was a master of Kremlin intrigues, and preferred the chess game of politics to the detail work of solving economic and social problems. He played top advisers off against each other, and never let any of them accumulate much power, lest they challenge him.

He fired the entire government four times in 1998 and 1999. The economy sank into a deep recession in summer 1998, but Yeltsin rarely commented on the troubles and never offered a plan to combat them.

He was quick to act if anyone threatened his hold on power, standing fast even when his traditional allies called on him to step down. He easily faced down an impeachment attempt by the Communist-dominated lower chamber of parliament in May 1999.

In foreign affairs, he struggled to preserve a role for his former superpower. He called for a "multipolar world" as a way to counterbalance what Russia perceived as excessive U.S. global clout, and in spring 1999 he sent Russian troops rushing to Kosovo ahead of NATO peacekeepers to underline that Moscow would not be elbowed out of European affairs.

He wrangled with the West in disputes over NATO expansion and Russia's relatively warm relations with Iran and Iraq. But as Russia's political and economic might withered, Yeltsin had little to offer other nations.

Boris Nikolayevich Yeltsin was born Feb. 1, 1931, into a peasant family in the Ural Mountains' Sverdlovsk region. When he was 3, his father was imprisoned in dictator Josef Stalin's purges. His alleged crime was owning property before the 1917 Bolshevik Revolution.

Yeltsin was, by his own account, a garrulous, scrappy boy who loved pranks and was quick to fight. And from the start, he bucked authority.

He was expelled from elementary school for criticizing a teacher at a school assembly. Early in his career as a construction engineer, he was given written reprimands 17 times in one year "a new record," he would later recall proudly. And his long career as a Communist Party official was rife with battles with higher party officials.

He was educated as an engineer and married a fellow student, Naina Girina. They had two daughters.

At age 30, Yeltsin joined the Communist Party after a brief career in construction in Sverdlovsk city, now Yekaterinburg. He became a full-time party official in construction in 1969, and seven years later was named the region's party boss.

In 1985, the new Soviet leader, Mikhail Gorbachev, intent on his own reforms, brought Yeltsin to Moscow, where he shook up the city's party hierarchy. The strapping, silver-haired Yeltsin cut a popular figure in the capital, making a point of riding city buses instead of a limousine, standing in long lines in grocery stores and loudly demanding why managers were stashing away food for favored customers instead of selling it to ordinary consumers.

A bitter rivalry soon grew between him and the more cautious Gorbachev. When Yeltsin criticized Gorbachev at a party meeting in November 1987, accusing him of a sluggish approach to reform, Gorbachev fired him.

In the old days, that would have ended Yeltsin's career. But he stormed back to power in 1989, winning a Soviet parliament seat in the first real election in 70 years. The following year, Yeltsin dramatically quit the Communist Party, walking out of its final convention.

His popularity grew. Yeltsin was a natural with crowds, shaking hands and bantering in a booming voice. For many Russians, he had the unpolished charm of a "muzhik" a tough peasant with common sense and a fondness for vodka.

Even then, Yeltsin's career was punctuated by bouts of bizarre behavior that the public chalked up to alcohol. Red-faced pranks, missed appointments, inarticulate and contradictory public statements continued into his presidency, blamed by aides on jet lag, medication or illness.

Yeltsin won Russia's first popular presidential election in a landslide in June 1991. Russia still was part of the Soviet Union, but the central government had started ceding power to the 15 republics.

Kremlin hard-liners trying to stop that process launched the failed coup in August, putting Gorbachev under house arrest. But Yeltsin took control of mass protests in Moscow, leading the democratic opposition to victory.

Yeltsin banned the Communist Party and confiscated its vast property. The ban was lifted in court about a year later, but by then Yeltsin had dealt the death blow to the tottering Soviet state. He and the leaders of Ukraine and Belarus formed the Commonwealth of Independent States in December 1991, declaring the Soviet Union extinct. Gorbachev resigned within the month.

Impatient to lead Russia into a new, prosperous era, Yeltsin quickly launched an economic-reform program that freed prices but sent them soaring, wiping out many people's savings. Inflation skyrocketed and production plummeted.

Years later, he expressed regret over the rush, and said he'd been "naive."

"I ask forgiveness for not justifying some hopes of those people who believed that at one stroke, in one spurt, we could leap from the gray, stagnant, totalitarian past into the light, rich civilized future," he told the nation in a televised speech to announce his resignation on Dec. 31, 1999.

"I myself believed in this, that we could overcome everything in one spurt."

Tension grew between him and the Soviet-era parliament, climaxing in fall 1993 when Yeltsin disbanded the legislature. An armed standoff and street riots followed, and Yeltsin finally turned tanks against the parliament building. Scores of people were killed in the fighting.

Afterward, Yeltsin pushed through a constitution that guaranteed a strong presidency and allowed him to brush off any serious parliamentary challenges.

But growing hard-line influence led him to dump key reformers from his Cabinet, which alienated democratic forces. Their disillusionment grew after the start of the first Chechnya war and more hard-line gains in parliamentary elections in December 1995.

By early 1996, Yeltsin was deeply unpopular and presidential elections loomed in June. But true to form, Yeltsin rallied when things looked bleakest, manipulating the media, enlisting the aid of the so-called oligarchs who had enriched themselves on the spoils of the Soviet economy in a grueling campaign.

The campaign trips to Russian regions and exertion took a heavy physical toll, and by election day Yeltsin could not even make it to his scheduled polling station. Doctors later said he had suffered another mild heart attack during the campaign.

He underwent quintuple heart bypass surgery in November 1996, but continued to suffer from a series of other ailments. He also had long-running back trouble, and seemed increasingly shaky, both physically and mentally.

Russians questioned who was running the country the doddering Yeltsin, or the aides and tycoons whom critics accused of exercising undue influence over Kremlin policy.

Yeltsin's increasing frailty seemed to reflect the declining fortunes of the country he led. During public appearances, he would often stumble, and his speeches were punctuated by long, inexplicable pauses even when he had the text in front of him.

Russians expected another halting speech on New Year's Eve 1999, but he stunned the nation and the world with his resignation having given no hint that he would ever give in to calls that he step down before his second term was up in spring 2000. He named his last prime minister, former KGB agent Vladimir Putin, acting president giving him a huge incumbent's advantage over any would-be challengers.

"Russia must enter the new millennium with new politicians, with new faces, with new, smart, strong, energetic people," Yeltsin said.

"And we who have been in power for many years already, we must go."

After his dramatic exit, Yeltsin appeared rarely in public popping up now and again at an official ceremony, holiday reception or tennis tournament. He traveled several times to China for what were described as health-boosting trips, and he looked fitter in retirement than he had in years.

Yeltsin met about once a month with Putin, usually at his dacha in Barvikha outside Moscow, he told an interviewer with Russian state television on the second anniversary of his resignation. He said he felt stronger than during the presidency, less weighed down by stress, and never regretted his abrupt departure. He felt certain that the reforms he championed would continue under Putin, he said.

"If I had doubts that the reforms might be reversed, I would not have resigned," Yeltsin said.