Two years after Walt Disney's death in 1966, Walker became executive vice president and chief operating officer. When Walt's brother Roy O. Disney died in 1971, Walker became company president, serving under chairman and CEO Donn Tatum. In November 1976 Walker took over chief executive officer duties from Tatum while retaining the responsibilities of president. Finally, in 1980 Walker became chairman of the Disney board upon Tatum's retirement. Walker himself retired as CEO three years later, in February 1983, but stayed on as chairman until May 1 to oversee the opening of Tokyo Disneyland in Japan.