The blog Lesben und Schwulenverband provides a timeline of the decades long effort to bring marriage equality to Germany.
7th July 2017: The Same-Sex Marriage Act passes the Bundesrat on 7th July. The act passes both chambers without a change to the constitution.
30th June 2017: Vote in the Bundestag: 393 deputies vote for equality, 226 are against, and four abstain.
28th June 2017: The Bundestag Committee on Legal Affairs recommends by majority vote that marriage should be opened to same-sex couples on the basis of the bill drafted by the Bundesrat.
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1990: In its first program of principles, the Gay Federation in Germany (SVD, today LSVD) calls for the right to marry for same-sex couples
1989: Denmark is the first country in the world to introduce civil partnerships for same-sex couples.
End of 1980s: Volker Beck, Günter Dworek and Manfred Bruns publish several papers calling for the establishment of a legal institution for same-sex couples – the first time such a call has been made in the Federal Republic of Germany. They judge the marriage ban for lesbians and gay men to constitute severe discrimination, and emphasize the importance of recognition of lesbian and gay partnerships to emancipation and acceptance within society.