Petraeus has a B.S. degree from the United States Military Academy, from which he graduated in 1974 as a distinguished cadet (top 5% of his class). In his class were three other future four-star generals, Martin Dempsey, Walter L. Sharp and Keith B. Alexander. He was the General George C. Marshall Award winner as the top graduate of the U.S. Army Command and General Staff College class of 1983. He subsequently earned an M.P.A. in 1985 and a Ph.D. degree in international relations in 1987 from the Woodrow Wilson School of Public and International Affairs at Princeton University. He later served as assistant professor of international relations at the United States Military Academy and also completed a fellowship at Georgetown University.