By 1942, neighbouring Burma was invaded by Japan, which by then had already captured the Indian territory of Andaman and Nicobar Islands. Japan gave nominal control of the islands to the Provisional Government of Free India on 21 October 1943, and in the following March, the Indian National Army with the help of Japan crossed into India and advanced as far as Kohima in Nagaland. This advance on the mainland of the Indian subcontinent reached its farthest point on Indian territory, retreating from the Battle of Kohima in June and from that of Imphal on 3 July 1944.