After more than 20 years, Blizzard Entertainment's senior VP of story and franchise development Chris Metzen is retiring.

Metzen joined the company when it was known as Chaos Studios, and has been a key figure in the development of Blizzard's flagship franchises.

Alongside fellow designer Bill Roper, Metzen created the fictional world of Diablo; he was also lead designer on Starcraft and creative director on Warcraft III: Reign of Chaos.

Metzen also created many of the novels, comics and expanded universe for Warcraft, Starcraft, and even Overwatch.

Additionally, Metzen has provided the voice for a number of Blizzard characters, the most notable being Thrall from the Warcraft franchise.

In a letter to the Blizzard community, Metzen spoke about his time with the company and bid farewell.

"I’ve never been more proud of Blizzard and the quality of its products than I am now," wrote Metzen. "It’s remarkable that even after all these years we can still reach new heights and take the world for an amazing ride. I believe Blizzard’s future is brighter than ever.

"I won’t lie—it’s going to be really hard stepping away from these worlds that I love. But I’m content that I’m leaving them in the hands of the most passionate, talented, and dedicated craftsmen ever assembled."

While co-worker Rob Pardo is leaving Blizzard to start Bonfire Studios, Metzen has stated that won't be the case for him.

"It’s been a long, amazing stretch of years," he added. "Now it’s time to slow it down. Rest. Lay around on the couch and get fat. Well, fatter.…

"Seriously though, I’ll be focusing on the one thing that matters most to me in all the world—my family. They’re the core of my life and the source of my deepest joy and inspiration. In addition to raising our two little ones, we recently welcomed our new baby into the family! Being home with them all, having time and space to really live…to love my wife with all my strength…that’s my career now."