MOSCOW -- Alexander Yakovlev, who spearheaded former Soviet President Mikhail Gorbachev's political reforms of openness known as glasnost and boldly exposed Communist crimes, died yesterday. He was 81.
Mr. Yakovlev died at his home in Moscow of an unspecified illness, said Oleg Pivovarov, a spokesman for the politician's International Democracy Foundation. Mr. Yakovlev suffered from high blood pressure and earlier in the day had visited the Kremlin Clinical Hospital, Pivovarov said.
As Gorbachev's righthand man, Mr. Yakovlev championed reforms that eroded the Communist Party's tight grip on political life and liberalized Soviet society.
Gorbachev called Mr. Yakovlev's death an ''irreparable loss."
''He made an enormous contribution to the democratic processes and the transformation of the country," said Gorbachev, who was on a trip to London, according to the ITAR-Tass news agency. ''He stood by the choice we made together -- in favor of freedom, democracy, human dignity -- to the end of his days. No obstacles, no accusations, succeeded in forcing him to change his position."
Mr. Yakovlev, born in the village of Korolyovo in the Volga River Yaroslavl region, fought in the Red Army in World War II and was badly wounded in 1943. He graduated from the history faculty of Yaroslavl University and became a Communist Party apparatchik.
He rose through the ranks, but was sent to Canada after a falling out with other members of the party's leadership and served as Soviet ambassador from 1973 to 1983. It was there that he had a fateful first meeting with Gorbachev in 1982, when the future leader was a visiting member of the Communist Party's ruling Politburo.
It was an electric encounter of like-minded men, Mr. Yakovlev recalled in a 1995 interview with the Associated Press.
''We were in an open field waiting for the arrival of an official," Mr. Yakovlev reminisced. ''We discussed everything, we interrupted each other and said, 'That thing must be changed and that one's intolerable . . . everything's intolerable.' "
After Gorbachev became Soviet leader in 1985, he quickly named Mr. Yakovlev to key party posts. In 1987, Mr. Yakovlev became the full member of the Politburo in charge of ideology.
As a senior adviser to Gorbachev, Mr. Yakovlev played a key role in encouraging media freedom. He fended off attacks from a die-hard wing of the Communist Party that fumed at news reports exposing Soviet dictator Josef Stalin's purges and other Communist crimes.
Mr. Yakovlev initiated the exposure of the secret 1939 Soviet pact with Nazi Germany that paved the way to the Soviet annexation of the Baltic nations of Estonia, Latvia and Lithuania.
He also actively contributed to Gorbachev's perestroika reforms that gradually narrowed the Communist Party's role and encouraged the development of nascent liberal parties.
''Yakovlev played a pivotal role in perestroika," Eduard Shevardnadze, Gorbachev's foreign minister and the former president of Georgia, told the Associated Press. ''He was a remarkable, greatly educated man."
Mr. Yakovlev said in the AP interview that his reformist efforts often brought disappointing results.
''I thought it would be enough to say 'Look people, you are free.' But intellectuals raised their heads, then started whining -- and everybody else did not give a damn," he said.
After fierce battles with Communist Party die-hards, Mr. Yakovlev quit the party just days before a failed August 1991 coup attempt by a group of hard-line Communists who wanted to oust Gorbachev.
Mr. Yakovlev, who could be brutally honest about his old boss, blamed the Soviet leader himself for bringing the plotters into his inner circle. Gorbachev was ''guilty of forming a team of traitors. Why did he surround himself with people capable of treason?" Mr. Yakovlev said.
''We often argued but always understood each other," Gorbachev said yesterday of Mr. Yakovlev, according to ITAR-Tass.
The failed coup hastened the collapse of the Soviet Union.
After its demise, Mr. Yakovlev became head of then-President Boris Yeltsin's commission for rehabilitation of victims of Soviet political repression. In that role, he remained a key figure in publicizing Soviet-era abuses.
In 2000, he attracted world attention by contending that Swedish diplomat Raoul Wallenberg had been shot to death in the Soviet secret police headquarters building in 1947. Wallenberg helped save thousands of Jews in Hungary in the waning months of World War II but disappeared after Hungary was occupied by the Red Army.
Mr. Yakovlev later established the International Democracy Foundation.
Yeltsin said yesterday that Mr. Yakovlev had done ''a great deal . . . for the development of democracy in Russia," the Interfax news agency reported.
Russia's President Vladimir Putin praised Mr. Yakovlev for his ''contribution to the nation's democratic revival and the development of civil society."
Mr. Yakovlev leaves his wife, son, and daughter.