Bahr was remembered on Thursday as a "brave", "honest" and a "luminous figure" for his work as righthand advisor to Chancellor Willy Brandt, creating the concept of “Ostpolitik” (eastern policy) that helped quell tensions between West Germany and the communist East.
"With great dismay and deep sorrow, we learned last night of the death of Egon Bahr," said Vice Chancellor and Social Democratic Party (SPD) leader Sigmar Gabriel in a statement on Thursday.
Gabriel praised Bahr as the "architect of German unity” and a "great intellectual thinker".
“His analytical brilliance, rationality and passion, as well as his character and charming sense of humour will be very missed," Gabriel continued. “I will miss him very much as a friend and an adviser."
Peaceful politics amid the cold
Bahr was born in 1922 in Treffurt, Thuringia. He grew into adulthood through the Nazi era and the Second World War, becoming a soldier in the Wehrmacht armed forces in 1942.
He was demoted after becoming a cadet because his grandmother was Jewish and was moved to a post as an armaments worker.
When the war ended, Bahr started working as a journalist for the Berliner Zeitung newspaper before becoming more politically active in West Germany.
In 1960, during Willy Brandt's term as mayor, Bahr became head of the Press and Information Office in the West Berlin city government.
Bahr would grow to become one of Brandt's most trusted advisors.
Construction of the Berlin Wall began one year after Bahr took on the information office position, solidifying the separation and tensions between East and West.
Lead role in negotiations
When Brandt took office as Chancellor in 1969, Bahr was named Secretary of State to the Chancellery as well as an appointed representative of the cabinet.
Bahr took a lead role in negotiating with Soviet leaders, advising on the Treaty of Moscow, which helped normalize relations between West Germany and the Soviet Union by renouncing force and agreeing to post-war borders.
Throughout these negotiations, Brandt exercised Bahr's proposal of “Ostpolitik” - eastern policy - a concept based on “change through rapprochement” to cooperate with East Germany.
Bahr called it a "policy of small steps".
"With Egon Bahr, his ideas of a radically new Ostpolitik and ‘change through rapprochement' altered the course of history and made German and European unity possible," Foreign Minister Frank-Walter Steinmeier said in a statement on Thursday.
Between 1972 and 1990, Bahr served as a member of the Bundestag (German parliament), serving under Brandt as Minister of Special Affairs and under Brandt's successor, Helmut Schmidt, as Minister for Economic Cooperation.
After the fall of the Berlin Wall, he continued to write about proposals for foreign policy, encouraging both Germany and Europe to take a more active, global role.
Last month, Bahr visited former Soviet leader Mikhail Gorbachev in Moscow, both men urging Russia and Germany to build back their trust of one another amid the Ukraine conflict.
"Reason without feeling is inhuman," Bahr once said, while "feeling without reason is stupidity."