Mongolia Expedition Force of China. 1914. Linsi (18.1) to Peking. Cover from the 24th Battlion of Yi Army stationed in Linsi to the Office of Northern Military in Peking. Franked with CIP overprinted ROC 3c, tied by Military Post Office 6, transit Military Relay Office 4 (23.1), arrived Peking (29.1). Scarce. The military post offices were set up to support the campaign to repulse an attempt by independent Mongolia to incorporate Inner Mongolia. In all, only a dozen such military covers survived.