Francis Bagnall Bessac (pronounced bih-ZAK; January 13, 1922 – December 6, 2010) was an American anthropologist who spent much of his life teaching the subject at the University of Montana, where he was appointed to the faculty in 1965. During the years toward the end of and immediately following World War II, Bessac served with the Office of Strategic Services (O.S.S.) in Western China and Mongolia, and while escaping from Communist Chinese forces in 1950 on their way to Tibet, Bessac was part of a group mistakenly attacked by Tibetan forces in which Central Intelligence Agency spy Douglas Mackiernan was killed, making him the CIA's first agent killed in action.
Bessac was born on January 13, 1922, in Lodi, California and earned his undergraduate degree at the University of the Pacific, where he majored in history. He enlisted in the United States Army during World War II. After studying Chinese language at Cornell University, Bessac was sent by the O.S.S. to China, where he served until 1947. He studied language at Fujen University in present-day Beijing after completing service with the O.S.S and was awarded a Fulbright scholarship.
The CIA hired him when it was formed in 1947, but Bessac left after realizing that the covert role the agency wanted him to fill would prevent him from further pursuing his studies of Mongolia. In the Gobi Desert studying anthropology in Inner Mongolia, Bessac was forced to flee in the wake of advancing Chinese Communist forces and decided to escape to Tibet by taking a journey of 2,000 miles (3,200 km) to Tihwa (now known as Ürümqi) and from there through Tibet and across the Himalayas to India.