Charlton manager Johnnie Jackson has left the League One club.
The 39-year-old was named interim manager in October before being appointed permanently in December.
The south London club won three of their last five league games and finished the season 13th in the table.
Charlton owner Thomas Sandgaard said it had been a "very difficult" decision to dispense with Jackson, whose contract renewal at the end of the campaign was dependent on results.
"I would like to thank Johnnie for everything he has done for the club," Sandgaard told the club's website.
"He is a Charlton legend who has given his all for this club as a player, captain, coach, assistant manager and manager.
"I am grateful for all he has contributed during my time at Charlton, including stabilising us this season when he took over as manager, following our poor start to the campaign.
"This decision has been a very difficult one to make, Johnnie has done so much for the club, but I felt the time was right to make the change as we continue our preparations for next season."
Jackson joined the club as a player on loan in February 2010, before joining permanently that summer, and played 279 games for Charlton, scoring 55 league goals.