Rare founders Tim and Chris Stamper have left the British developer as the company enters its 25th year, Microsoft has confirmed.
Microsoft, which bought Rare for $375 million in 2002, told 1UP that the Stampers "are simply leaving to pursue other opportunities" and wished them luck.
"Chris and Tim have helped shape Rare into the world-renowned development studio that is it today and their impact on the videogame industry as a whole is well known," the platform holder said in a statement.
Mark Betteridge, a 19-year veteran of the Twycross studio, and Gregg Mayles have been promoted to studio and creative director respectively.
Rare has been under increased scrutiny since the company's record-breaking buyout in 2002, but the critical response to its most recent title, Viva Piñata, has been uniformly positive.
The game placed 8th in our Top 50 Games of 2006, voted for by around 20 contributing writers. And I've got a lion and you haven't.
The company is currently known to be at work on a Banjo Kazooie title for Xbox 360, reviving the once-celebrated N64 series, with at least two other projects thought to be in development elsewhere on the Twycross campus.
To read some of new creative director Gregg Mayles' views on nurturing intellectual property and the role of multimedia, be sure to have a look through an interview with him conducted by our sister site GamesIndustry.biz.