The race is on to succeed Angela Merkel, by becoming leader of Germany's centre-right Christian Democrats (CDU) and potentially chancellor.
She will not run again in Germany's next general election, due by October 2021.
It is the end of an era: Mrs Merkel has been steering Germany and shaping EU policy since 2005.
Now three candidates, all men, have joined the race to lead her party.
The woman she favoured to succeed her as chancellor - Annegret Kramp-Karrenbauer - resigned as party leader this month when the CDU was tainted by a political scandal in the state of Thuringia.
A deal with the far-right Alternative for Germany (AfD), now annulled, put a liberal in charge of Thuringia thanks to AfD and CDU votes. It broke a post-war German taboo: no deals with the far right or far left.
Then came a humiliating blow to the CDU in Hamburg: in the regional election there the CDU got 11.2%, far behind the centre-left Social Democrats, who won, and the Greens.
So, rough times for the CDU. But it is still favourite to win the next national election, with its Bavarian sister party, the CSU. So who could succeed Chancellor Merkel in the CDU members' vote on 25 April?
Friedrich Merz - conservative 'fresh start'
There is a legal vacuum in too many places in Germany
The 64-year-old, like his rivals, is from North Rhine-Westphalia (NRW) - Germany's most populous state, dominated by the Ruhr region's heavy industry.
He trained as a lawyer and used to lead the CDU/CSU parliamentary group. A millionaire with wide-ranging business connections, he casts himself as the candidate of "a fresh start and CDU renewal".
But it is his second bid for the top job: he narrowly lost to Ms Kramp-Karrenbauer in 2018.
Presenting his agenda, he emphasised law and order - a message that plays well with the CDU's conservative wing.
In too many areas in Germany "there is a legal vacuum", he complained, and pledged to curb illegal immigration.
Prof Oskar Niedermayer, a politics expert at the Free University of Berlin, says "the CDU grassroots prefer Merz, all the surveys show he is ahead, and he is far ahead among the voters".
"He wants to strengthen the CDU's conservative policies and get AfD voters back."
Before becoming a Bundestag MP he was an MEP in the European Parliament. He left politics in 2009 over a policy dispute with Mrs Merkel, and had a succession of top business jobs. He served on company boards and managed the German investments of US finance house Blackrock.
Armin Laschet - liberal close to Merkel
We are economically strong, successful. But despite that, there is a lot of dissatisfaction in society, so much aggression, so much anger, so much hate
Mr Laschet, 59, is premier of the NRW region and emphasises "social cohesion" as a key goal, as he sees "so much aggression, so much anger" in Germany now.
He is seen as the "Merkel continuity" candidate. Prof Niedermayer told the BBC that "he is very close to Merkel on refugee policy".
However, he now has an influential ally in Jens Spahn, a more conservative figure who has teamed up with him and could woo CDU conservatives. Mr Spahn had been expected to run for the leadership himself.
In the CDU's higher echelons the Merkel camp is strongest, Prof Niedermayer says, adding that Mr Laschet "is more capable of forming a coalition with the Greens".
Coalition politics will influence this race. The CDU is governing Germany with the Social Democrats (SPD), but nationally the SPD has haemorrhaged support, while the Greens have gained ground. A future CDU-Green coalition is a strong possibility.
Like Mr Merz, Armin Laschet also served as a Bundestag MP previously, then as an MEP. A practising Roman Catholic, he has been a key figure in NRW regional politics since 2005.
Norbert Röttgen - green bid for centre ground
Currently Germany is a total failure. I can't recognise any Europe policy, the foreign minister is a failure, the chancellor knows all this, but does nothing
Like Mr Laschet, Norbert Röttgen used to have regular talks with Green Party politicians in what was dubbed the "Pizza Connection", because they met at an Italian restaurant.
Mr Röttgen, 54, was German environment minister in 2009-2012, but Mrs Merkel sacked him when he lost a key election in NRW in 2012.
He is a strong critic of Mrs Merkel so, like Mr Merz, he is not in her camp. He had not been expected to enter the leadership race.
Prof Niedermayer sees Mr Röttgen as an outsider in this race, because "he doesn't have a party association behind him, and he's not very close to the grassroots".
Mr Röttgen currently chairs the Bundestag's Committee on Foreign Affairs.
He has called for new faces at the top of the CDU, arguing that women "belong in the most prominent place in the CDU" - and he has vowed to make that a reality, not just words.