Mike Morhaime, co-founder of Blizzard Entertainment and the studio’s longtime president, has stepped down from his position effective immediately. While Morhaime will stay on as a strategic adviser, World of Warcraft executive producer J. Allen Brack has taken over as president of Blizzard Entertainment, the company announced Wednesday afternoon.

Brack has been with Blizzard for 12 years, and has led the World of Warcraft team for that duration. Alongside Brack, chief development officer Ray Gresko and Blizzard co-founder Allen Adham have also joined the studio’s executive leadership team.

As for Morhaime, he shared his gratitude to the Blizzard community as part of the announcement.

“I want to thank all of the talented and hardworking people at Blizzard for their dedication, creativity and passion,” said Morhaime. “It has been a privilege to lead this team. I’m also very grateful to Blizzard‘s player community for their support.”

Morhaime co-founded Blizzard as Silicon & Synapse in 1991, and had served as its president since 1998; he also took on the CEO role in 2007. In addition, he contributed to many of the company’s games as a developer, including roles as a programmer, producer or executive producer on titles such as The Lost Vikings, all three Warcraft games, the first two Diablo games, the original StarCraft and World of Warcraft. Morhaime was inducted into the Academy of Interactive Arts and Sciences’ Hall of Fame in 2008. He also happens to be the bass player for Blizzard’s in-house metal band, Elite Tauren Chieftain (called ETC).

Wednesday’s announcement comes only two years after Blizzard veteran Chris Metzen retired from the company. Blizzard fans will likely hear more about this transition when BlizzCon 2018 begins in November, as Morhaime traditionally gives the opening keynote there.

Longer messages to the Blizzard community from both Morhaime and Brack can be found on the company’s website.

Correction: Blizzard announced this news on Oct. 3, which is a Wednesday, not a Thursday. We’ve edited the story to reflect this.