Wolfgang Schaeuble, one of the most important figures in German political life over the last 30 years, has died aged 81, a source from the conservative CDU-CSU alliance told AFP on Wednesday.

Schaeuble, who was a minister under chancellors Helmut Kohl and Angela Merkel and played a key role in German reunification in 1990, died peacefully in the night, the Bild daily reported.

Chancellor Olaf Scholz said Schaeuble had "shaped our country for more than half a century".

"Germany has lost a sharp thinker, passionate politician and pugnacious democrat," Scholz wrote on X, formerly Twitter.

Born in Freiburg in 1942, Schaeuble was the longest-serving member of Germany's Bundestag lower house of parliament, where he had sat since 1972.

It was under former conservative leader Kohl that the pro-European Schaeuble forged his career, rising through the ranks to eventually become Kohl's chief of staff, and was long seen as the chancellor's heir apparent.

Together they oversaw Germany's national reunification, before personal tragedy struck Schaeuble -- an assassination attempt by a deranged man in 1990 badly injured him and forced him to use a wheelchair for the rest of his life.

As finance minister for several years under Merkel, Schaeuble carved out a reputation as the guardian of German budgetary rigour, particularly during the Greek debt crisis.

"There is hardly another politician who has shaped recent German history and our democratic culture as much as Wolfgang Schaeuble," Foreign Minister Annalena Baerbock wrote on X, praising his "outstanding services to German and European unification".