President Donald Trump abruptly fired Air Force Gen. CQ Brown Jr. as chairman of the Joint Chiefs of Staff on Friday, sidelining a history-making fighter pilot and respected officer as part of a campaign led by his defense secretary to rid the military of leaders who support diversity and equity in the ranks.

Trump said he plans to nominate Lt. Gen. Dan “Razin” Caine of the U.S. Air Force to replace Gen. CQ Brown as the nation’s top-ranking military officer.

The decision to fire Gen. Charles Q. Brown Jr., a four-star fighter pilot, upends a tradition in which the Joint Chiefs chairman traditionally remains in place as administrations change.