Relics of command posts of American Volunteer Groups (AVG) are located at the piedmont of Jigong Mountain, south China's Guangxi. Claire Lee Chennault, authorized by then U.S. Present Franklin Roosevelt, formed The Chinese Air Force of AVG in 1941. This volunteer group got the name Flying Tigers since there is a flying tiger on their emblem. The AVG moved to Guilin Yangtang Airport on June 11, 1942, shouldering responsibilities of air defense and to annihilate Japanese marine transport ships. The front-line headquarter of the American 14th Air Force moved from Kunming to Guilin on December 23, 1943. Both the headquarters and command posts were in the caves in two mountains at Yangtang Airport. Since then, all commands and reports were sent from here.