Founded in 1948, the liberal pro-business FDP participated in German governments led by the CDU and the SPD as a junior partner for a total of 45 years - before dropping out of parliament after the 2013 general election.
The FDP promotes free market economy and individual liberty and had a reputation as a "king maker" for both Germany's big parties, neither of whom have managed to get an absolute majority for decades. Frequently, the FDP emerged as a viable junior coalition partner. The FDP's critics alleged that the party catered only to its voter base of urban, wealthy, self-employed Germans - such as pharmacists, hotel owners, lawyers and doctors. It failed to get more than 5% of the vote in the 2013 election and therefore dropped out of the Bundestag. The party is seeking to recover its national parliamentary representation in the 2017 elections. Recent DW stories tagged "FDP" appear on this page.
After its defeat in the North Rhine-Westphalia state election, the center-left SPD has rejected a coalition with Angela Merkel's CDU. The news might be a boon to the resurgent business-friendly FDP - also nationally.
The FDP emerged victorious from the pivotal state election in Germany's most populous state and now have their eyes firmly on Berlin. Here's what you need to know about the small party that could hold the keys to power.
Winning Germany's most populous state - the last to vote before September's general election - could provide key momentum. And there are many other reasons why parties want a strong showing in North Rhine-Westphalia.
It's been a long time since there's been this much political uncertainty in Germany. The general election is still a year away, but the refugee crisis has had a major impact on politics. Here's where the parties stand.