Alexei Botyan, a veteran of Soviet intelligence hailed for saving the Polish city of Krakow from being blown up by the Nazis during World War II, has died at 103.

Russian President Vladimir Putin hailed Botyan as a “legendary intelligence officer” and a “true patriot” in a telegram of condolences.

Botyan died in Moscow on Thursday just three days after his 103rd birthday.

Born in 1917, Botyan grew up in Poland and took part in fighting with the Nazis as a Polish army soldier at the start of World War II. He then moved to the Soviet Union and was trained as an intelligence operative.

When the Nazis invaded the Soviet Union, Botyan was sent behind enemy lines to join Soviet guerrilla groups in Ukraine and Belarus, In 1944, when theSoviet Red Army pushed the Nazis back beyond the Soviet border, Botyan was dispatched to Poland.

In January 1945, Botyan oversaw an operation to destroy a depot of explosives that the Nazis had planned to use to blow up Krakow. The operation was later featured in a popular Soviet spy novel and a movie.

After the war, Botyan continued to work as an intelligence officer until he retired from the KGB in 1989. In recent years, he gave numerous interviews to Russian television and other media to describe his Krakow actions.

In 2007, Putin awarded Botyan Russia’s highest honor, the Hero of Russia medal.