X Force was the name given to the portion of the National Revolutionary Army's Chinese Expeditionary Force that retreated from Burma into India in 1942. Chiang Kai-shek sent troops into Burma from Yunnan in 1942 to assist the British in holding back the Japanese. These Chinese forces became broken up, and in the retreat out of Burma part of these forces entered India. These were cantoned at Ramgarh Cantonment in the Bihar Province (now in Jharkhand State), brought up to five-Division strength (Chinese New 30th, New 22nd, New 38th, 14th and 50th Divisions), and re-equipped and re-trained by American instructors at British expense.