Joachim Gauck has been elected German President by an overwhelming majority, marking the first time a candidate from the former communist east will be head of state.
Mr Gauck, 72, claimed 991 votes out of 1,232 from a special assembly of MPs and other dignitaries, parliamentary speaker Norbert Lammert said.
Prominent Nazi hunter Beate Klarsfeld, 73, had been nominated as a protest candidate by the far-left party Die Linke.
"What a beautiful Sunday," Mr Gauck said to enthusiastic applause from the chamber of the Reichstag parliament building in Berlin after the vote.
It was the third presidential election in three years for Germany after the abrupt resignations of Mr Gauck's two predecessors.
Mr Gauck helped drive the peaceful revolution that brought down communist East Germany.
He later fought to ensure that the public would be granted access to the vast number of files left behind by the Stasi secret police after reunification in 1990 and oversaw the archive for the next decade.
Chancellor Angela Merkel gave her backing to Mr Gauck in February after President Christian Wulff stepped down over corruption allegations dating from his time as a state premier.
Mr Wulff only served 20 months of his five-year term in office.
He had replaced Horst Koehler, a former head of the International Monetary Fund, who bowed out after an uproar over comments he made appearing to justify using the military to serve Germany's economic interests.
