@SubArcticTundra@lemmy.ml To add to the above comment: in the early years of the Federal Republic the FDP was more or less the king maker. SPD and CDU had the major share of votes but needed a coalition partner to form the government. FDP was the third party in parliament and thus the only option.

This early FDP had a social-liberal wing as well (mostly in northern Germany) which would make coalitions with the SPD possible.