The head of the Russian Presidential Administration's medical center said Yeltsin died of "cardiovascular inefficiency" at 3:45 p.m. local time (7:45 a.m. EDT).
Larger than life during his tenure, Yeltsin shrank from public view following his retirement on New Year's Eve 1999, and in recent years has rarely given interviews. By the time the Kremlin announced his death in a Moscow hospital, he seemed like a figure from Russia's distant history.
Russians today prefer to recall the glory of the Soviet era, not the suffering that followed its implosion, and the initial announcements of his death on state-run and private channels were followed quickly by soap operas and fashion programs. One network, NTV, began continuous coverage in the evening, but there was little sense of a nation in mourning.
President Vladimir Putin's statement came some four hours after the death was announced. He praised Yeltsin as a man "thanks to whom a whole new epoch has started. New democratic Russia was born, a free state open to the world; a state in which power truly belongs to the people."
Yeltsin is to be buried Wednesday in Moscow's historic Novodevichy cemetery, the resting place of such diverse figures as Nikita Khrushchev and Anton Chekhov.
CBS News correspondent Elizabeth Palmer says Yeltsin "wasn't politically correct, but he was politically astute."
After starting his career as a Communist party boss, Yeltsin left the party in 1990 and successfully re-invented himself as a democrat, reports Palmer.
Yeltsin sometimes seemed to have spent his years as Russia's first freely elected president in retreat from the reforms he so theatrically demanded as a Communist Party leader and exultant wrecker of the totalitarian regime.
He presided over the abolition of the old KGB, but then named a KGB veteran as his heir apparent.
However, what angered many Russians was how Yeltsin the crusader against Soviet corruption presided over a fire sale of state-owned industries to Kremlin insiders, which created a small cadre of Russian billionaires overnight.
Meanwhile, during his tenure many ordinary Russian citizens saw their savings wiped out, their jobs evaporate, the society their parents and grandparents had created disintegrate.
"He was one of us," said Galina Alexandrovna, a Moscow resident, recalling the heady days after the Soviet collapse. "When we elected him we all shouted, 'Hurrah for Boris Yeltsin' but then Russia started selling itself off and we the simple people didn't like what was happening."
Mikhail Gorbachev, the last Soviet president, eulogized Yeltsin, both a comrade and a nemesis, as one "on whose shoulders are both great deeds for the country and serious errors," according to the news agency Interfax.
Perhaps frustrated by Russia's stumbling out of the gate after the Soviet era, he increasingly concentrated power in his own hands — and finally handed it over to Putin, the former KGB colonel who rose rapidly through the Kremlin ranks.
After Putin took power, he was careful to cultivate the image of the anti-Yeltsin. The second Russian president always appears sober where Yeltsin often was not; Putin is decisive where Yeltsin waffled, firing Cabinet after Cabinet. Putin appears calculating where Yeltsin could be spontaneous, to the point of being impulsive.
Yeltsin's greatest moments, in fact, came during fitful flashes of inspiration and surges of energy.
Yeltsin cast himself as a fearless defender of Russia against tyranny in August 1991, adds Palmer, when he jumped on a tank and rallied Russians against a coup threatening then-Soviet leader Gorbachev. But within months, the Soviet state itself had fallen and Yeltsin had seized power from Gorbachev.
Ill with heart problems, and facing possible defeat by a Communist challenger in his 1996 re-election bid, Yeltsin somehow sprinted through the final weeks of the campaign. The challenge transformed the shaky convalescent into the spry, dancing candidate.
"A man must live like a great bright flame and burn as brightly as he can," Yeltsin once said. "In the end he burns out. But this is better than a mean little flame."
But Yeltsin could not be bothered with the trifling tasks of day-to-day government and was quick to blame subordinates for Russia's multiplying problems.
He seemed to be a democrat by instinct, in a nation that had never known democracy. But as the years passed, he increasingly concentrated power in his own hands. And when there was trouble, he frequently resorted to force to quell dissent, claiming only an iron hand could keep the country together.
He sent tanks and troops in October 1993 to flush armed hard-liners out of a hostile Parliament after violence in the streets of Moscow. And in December 1994, Yeltsin launched the first of two of Russia's wars against separatists in the southern republic of Chechnya, conflicts that would turn the Chechen capital of Grozny into a wasteland and cost the lives of tens of thousands.
Sometimes, Yeltsin seemed overwhelmed by his responsibilities. Viktor Chernomyrdin, one of his prime ministers, said Monday that Yeltsin's health never recovered from the stress of trying to steer Russia through some of its darkest hours.
"Yeltsin headed the country during the most difficult time and it could not but affect the health of even such a strong man," said Chernomyrdin, now Russia's ambassador to Ukraine.
Admirers contend that it was the trauma of the USSR's death throes, not Yeltsin's leadership, that brought Russia to the brink.
"If not for the strong will of Boris Nikolayevich, we cannot rule out that after Gorbachev, Russia could have plunged — for many, many years or even decades — into civil war," said Vyacheslav Kostikov, a former Yeltsin press secretary.
In the final years of his presidency, 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 stumbled from crisis to crisis, its leader appeared increasingly absent.
Yet Yeltsin's debut as Russian president was stunning. He laid the foundation for what many hoped would later become a modern democracy — guaranteeing the rights to free speech, private property, 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.
"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 warmly embraced Western leaders.
Throughout his nearly decade-long leadership, he remained Russia's strongest bulwark against Communism.
"What set him apart was that he very often defeated his opponents, but he never trampled on them," said Grigory Yavlinsky, the head of Russia's marginalized liberal Yabloko party. "He would knock an opponent off his horse, but never destroy him. In his time, there were many shortcomings and even crimes, but ... there was never any physical removal of political opponents in Russia, and that was his personal contribution."
But there was another Yeltsin.
He was hesitant to act against rampant crime and epic corruption, beginning in his own administration, as both sapped public faith and crippled the young democracy. His government's wrenching economic reforms impoverished millions, 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 by a staggering 75 percent, and the nation's population fell by more than 2 million. Vodka consumption soared.
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 fired the entire government four times in 1998 and 1999. The economy sank into a deep recession in the summer of 1998, but Yeltsin rarely commented on the troubles and never offered a plan to combat them.
While he seemed to lurch from policy to policy, he seemed steadfast in his determination to hold onto power. 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 Russia, which for centuries had defined itself as one of the great world powers.
He called for a "multipolar world" as a way to counterbalance U.S. global clout, and in spring 1999 dispatched Russian troops to Kosovo, ahead of NATO peacekeepers, to underline that Moscow would not be elbowed out of European affairs.
He wrangled with the West over NATO expansion and Russia's close relations with Iran and Iraq. But as Russia's political and economic might withered, Yeltsin had little to offer other nations.
In recent years, Yeltsin has rarely discussed his legacy. He has criticized Putin only rarely — once, in 2000, for Putin's decision to revive the old Soviet anthem, and again in 2004, when Putin announced he would end the direct election of governors.
In both cases, Yeltsin's one-time protege dismantled some of his mentor's reforms.
Boris Nemtsov, a leader of the liberal Union of Right Forces, noted that Yeltsin "loved freedom" and in the end protected the free press and Russia's multiparty democracy.
"All these achievements are now being destroyed, and I would say destroyed cruelly and mercilessly," he told Echo Moskvy radio. "I think the best way to remember Yeltsin would be if we return freedom to our country."
Just last year, though, Yeltsin defended his choice of Putin in an interview with the newsweekly Itogi, saying without a "strong hand" the country would have disintegrated.
Yeltsin is survived by his wife, Naina, two daughters and several grandchildren.