At the age of 18, he joined the Army when he was accepted to West Point. Peake received his Bachelor of Science degree from U.S. Military Academy at West Point in 1966 and was commissioned a second lieutenant in the U.S. Army Infantry. Following service in Vietnam with the 101st Airborne Division where he was awarded the Silver Star, a Bronze Star with “V” device and the Purple Heart with oak leaf cluster, Peake entered medical school at Cornell University in New York. He was awarded a medical doctorate in 1972. He retired from the Army in 2004, as a Lieutenant General.