After the invasion of the Philippines by the Japanese in 1941, several Americans, civilian and military, evaded capture or escaped imprisonment. This occurred on several islands in the archipelago. With the aid of the local Philippine population, these Americans survived. However, not content with just surviving and avoiding capture, these Americans formed resistance groups, which were soon recognized by the American military, and eventually supplied. Initially relegated to an intelligence gathering role, these groups eventually took a more active and aggressive role, such that they were an integral part of the American re-conquest of the country.