Robert Bowling, Creative Strategist for Infinity Ward, announced his resignation today over twitter.
He has held the position for six years, working on the Call of Duty: Modern Warfare series since its launch in 2007.
"Today, I resign from my position as Creative Strategist of Call of Duty, as a lead of Infinity Ward, and as an employee of Activision," he wrote.
In 2003, Bowling enlisted in the U.S. Army.
He recieved a great deal of attention when he publicly denounced a statement made by Activision senior producer Noah Heller, who had compared Call of Duty: World at War to Call of Duty 4: Modern Warfare.
Bowling is the CEO and founder of PR and marketing firm Fourzerotwo Media, and co-founder and editor in chief of Substream Magazine.
Neither Activision or Infinity Ward have released their own statement on the resignation.