Michael Glenn "Mike" Mullen (born October 4, 1946) is a retired United States Navy admiral, who served as the 17th Chairman of the Joint Chiefs of Staff from October 1, 2007 to September 30, 2011. Mullen previously served as the Navy's 28th Chief of Naval Operations from July 22, 2005 to September 29, 2007. He was only the third naval officer in Navy history to be appointed to four different four-star assignmentsthe others being the Commander, U.S.