Nagelsmann had taken over in 2021 and led them to their 10th straight German league crown but failed to advance deep in Europe last season.

''FC Bayern Munchen has released head coach Julian Nagelsmann. This decision was taken by CEO Oliver Kahn and board member for sport Hasan Salihamidzic in consultation with club president Herbert Hainer.'' The club said in a statement.

''Nagelsmann will be succeeded by Thomas Tuchel. Tuchel will receive a contract until 30 June 2025 and will supervise squad training for the first time on Monday.''

His surprise departure comes as Bayern prepare to face league leaders Borussia Dortmund next week in the Bundesliga and Manchester City in the Champions League quarter-final on April 11.

"We came to the conclusion that the quality of our squad was less and less visible despite winning the league last season," Bayern CEO Oliver Kahn said.

"After the World Cup we were playing less successful and less attractive football and the ups and downs in our form put our season goals, and beyond, at risk. That is why we reacted now."

Nagelsmann's successor Tuchel, who had been a long-time Bayern target since their first attempt to sign him in 2018, has penned a deal to 2025, Bayern said.

Tuchel won the Champions League for Chelsea in 2021 after replacing Frank Lampard, but has been without a job since being sacked by the English side last year.

He built a reputation as a forward-thinking tactician in the Bundesliga during his time at Mainz 05 before taking over at Dortmund and leading them to German Cup success in 2017.

The 49-year-old also delivered back-to-back French league titles during his time at Paris St-Germain and took them to their first Champions League final in 2020, which they lost to Bayern.

A perfectionist and master tactician, Tuchel is equally known for his at times difficult relatonships with club bosses, including at Dortmund and Chelsea.