"Hans-Dietrich Genscher died last night at the age of 89 in the presence of his family at his home in Wachtberg-Pech, of cardiovascular failure," said a statement by his private office.
Genscher was among a select few politicians who left a strong personal mark on the course of postwar European history, and tributes poured in immediately.
Chancellor Angela Merkel's deputy spokesman Georg Streiter said "I almost feel too small... To honour this great statesman, this great European, this great German."
When he took office, Europe looked to be forever divided into two nuclear-armed camps.
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When he stepped down, Germany was reunited and Soviet communism had been consigned to history.
Genscher -- who served in both centre-left Social Democrat and conservative Christian Democrat governments -- was a tireless advocate of consensus, European integration and East-West cooperation in the pursuit of the peaceful unification of Europe.
He strongly favoured dialogue over demonising the Soviet Union, an approach known in Germany as "Ostpolitik", and argued early that Mikhail Gorbachev's glasnost and perestroika (openness and restructuring) reforms presented a historic opportunity for detente.
His landmark moment was a 1989 speech at the German embassy in Prague, where the courtyard was packed with thousands of East Germans desperate to head west.
Genscher spoke from the balcony to announce a deal with the Czech communist government allowing them safe passage.
"We have come to you to tell you that today your departure..." he told them. The rest of the sentence is lost to history as it was drowned out by jubilant cheers.