Sergei Kovalev, a well-known human rights activist and former Soviet dissident, died on Monday at the age of 91, according to his family.
Kovalev was a biologist who rose to prominence in the Soviet Union’s pro-democracy movement. For his activities, he was imprisoned in Soviet labor camps.
When President Vladimir Putin came to office in 2000, he became a harsh critic of Moscow’s war in Chechnya and warned against democratic backsliding following the dissolution of the Soviet Union.
Ivan Kovalev, his son, wrote on Facebook that his father died “in his sleep” early Monday morning.
Memorial, a Russian human rights organization that Kovalev formerly chaired, said he was “always and in everything committed to the principle of human rights — in war and peace, politics and every day life.”
Kovalev has battled for human rights since 1969, according to the prominent rights organization, which has been labeled a “foreign agent” by Russian authorities under a controversial statute.
It claimed on Facebook that “he persistently fought for the same ideas” in post-Soviet Russia.
In 1994, Kovalev was appointed chairman of President Boris Yeltsin’s human rights commission. He was a dissident under the late Soviet leader Leonid Brezhnev.
For his open condemnation of Russia’s violent engagement in the Chechen conflict, he was fired.
Kovalev also slammed Putin’s political system, which he helped construct as a former KGB spy.
In July 2001, two months after Putin was inaugurated as president, he declared, “A controlled democracy is being formed in our nation that attempts to cause issues for ‘enemies inside as well as outside.”