MOSCOW (Reuters) - Former Russian President Boris Yeltsin, who buried the Soviet Union then led Russia through its chaotic first years of independence, has died, the Kremlin said on Monday. "Boris Yeltsin died in Moscow today," a Kremlin spokeswoman said by telephone. Russian media reported that Yeltsin, 76, died of heart failure after years of being dogged by cardiac problems that required several major operations. Many Russians initially viewed Yeltsin as a hero for dismantling Communist rule. But his economic "shock therapy" cast millions into poverty and his last years in office were marked by chaos, persistent reports of drunkenness and bloody fighting in Chechnya. Mikhail Gorbachev, the last Soviet president whom Yeltsin effectively forced from office, paid tribute to his achievements, and noted his shortcomings. "I express the very deepest condolences to the family of the deceased on whose shoulders rest major events for the good of the country and serious mistakes," Gorbachev. "A tragic fate," said Gorbachev, who had bitter relations with Yeltsin in his lifetime. In Washington, a spokesman for the White House National Security Council described Yeltsin as "a historic figure during a time of great change and challenge for Russia". "Our condolences go to Mrs Yeltsin, their family and the people of Russia," said Gordon Johndroe. Yeltsin ruled Russia from 1991 to the last day of 1999, when he handed over power to Vladimir Putin. He had the distinction of becoming the first Russian leader to step down voluntarily. Many of Yeltsin's contemporaries in the democracy movement alleged Putin had betrayed Yeltsin's legacy by dismantling democracy, but once in retirement he never returned to public politics.