The premier of the western German state of Rhineland-Palatinate, Malu Dreyer, announced her resignation on Wednesday.
Dreyer, a Social Democrat who has led the state since 2013, said she no longer had the energy required for the job and would step down from the post in July.
"I am leaving with a heavy heart because I am not tired of the job," Dreyer said in Mainz, the state capital.
But Dryer said the work has become draining and she must muster more and more energy for the job, which is pushing her to her limits.
"I'm 63, so I'm not very old yet. But I have to admit to myself that it's not the same as when I was 50," she said.
Dreyer's resignation comes less than two weeks after her Social Democratic Party (SPD) suffered a major defeat in European Parliament elections, and also lost ground in local elections held in the state.
Dreyer said that Alexander Schweitzer, another Social Democrat, will be her replacement. He currently serves as the state's minister for labour and social affairs. Dreyer said Schweitzer was unanimously selected for the post by the SPD's faction in the state parliament.
That would give the 50-year-old Schweitzer the opportunity to head into the next state parliamentary election - scheduled for 2026 - as an incumbent.
In her remarks, Dreyer described the catastrophic and deadly 2021 floods in the Ahr Valley in the state as a painful turning point in her life. Dreyer faced intense criticism over the handling of the disaster.
"It was also a painful turning point for me, which also divides my life or my life into a time before and after," she said on Wednesday.
Political scientist Uwe Jun said on Wednesday that Dreyer had chosen a good time to step down with less than two years before the next state election.
Jun told dpa that her successor will have enough time to take office and make his mark, although Jun said that Schweitzer has "very big shoes to fill" given Dreyer's long tenure and very high popularity ratings among voters in the state.
Dreyer said she plans to take a rest and "simply do nothing" for a bit once she leaves the job in July.
The main challenger for the post in 2026 is expected to be Gordon Schnieder of the centre-right Christian Democrats (CDU).
The SPD has held power in the state since 1991, but lost ground in the recent voting. Sources in both the SPD and CDU had said that state party leaders planned to begin preparations for the 2026 vote after the EU elections.
Sources told dpa that two other Social Democrats - state Interior Minister Michael Ebling and state parliamentary group leader Sabine Bätzing-Lichtenthäler - had also been considered as possible successors to Dreyer.
On Wednesday, long-time state SPD party chairman for Rhineland-Palitanate, Roger Lewentz, also announced plans to resign. Dreyer said that he will be replaced by Bätzing-Lichtenthäler.
