BERLIN: Germany's longest-serving foreign minister Hans-Dietrich Genscher, a one-time refugee from the Communist East who helped unite his divided homeland, has died at the age of 89.

Genscher died of heart failure at home surrounded by his family on Thursday night, his office said in a statement on Friday.

Genscher, a lawyer who joined the liberal Free Democrats (FDP) party after fleeing East Germany, reached the height of his power as reunified Germany's first foreign minister.

FDP leader Christian Lindner said on Twitter that Genscher had made history, calling him "the architect of unity (and) one of the founders of the EU".

Compared by some commentators to US Secretary of State Henry Kissinger and Napoleon's foreign minister Talleyrand, Genscher employed his diplomatic skills to win support for reunification among doubting allies and former enemies.

With then chancellor Helmut Kohl, Genscher persuaded Moscow to give up its staunchest Cold War ally and let it join the former “enemy.

And by stressing the then Bonn government's total commitment to the West and the European integration he championed, Genscher helped reassure Western allies wary of the rebirth of a strong Germany.

His persistence was rewarded on October 3, 1990, when West and East Germany were reunified after signing a treaty with the four victorious World War Two powers to restore German sovereignty after 45 years.

German government spokesman Georg Streiter said Genscher was "a great statesman, a great European and a great German".

Born on March 21, 1927, at Reideburg, near Halle, Genscher served in the Luftwaffe (air force) towards the end of World War Two. He said it was only many years later that he learned his name was entered in the rolls of Nazi Party members.

He suffered his worst political moment in 1972, as interior minister, when a police operation to rescue Israeli athletes kidnapped by Palestinians at the Munich Olympic Games ended with the deaths of 11 members of the Israeli team.

Two years later he became foreign minister, a position he held without interruption until 1992.

A passionate supporter of the European Union, Genscher also helped pave the way for the euro with a memorandum on a European central bank and a unified currency area, one of the early steps that led to the launch of the common currency in 1999.

More controversially, he was instrumental in Germany's quick recognition of an independent Croatia in 1991, a decision considered by many to have been a trigger for the uncontrolled breakup of the former Yugoslavia and the region's subsequent slide into war.