Martin Edward Dempsey (born March 14, 1952), sometimes known as Marty Dempsey, is a retired United States Army general. He was the 18th Chairman of the Joint Chiefs of Staff from October 1, 2011 until September 25, 2015. He was the 37th Chief of Staff of the Army from April 11, 2011 to September 7, 2011. He retired on September 25, 2015. 