for the most part of philippines' history, the region and most of mindanao have been a separate territory, which enabled it to develop its own culture and identity. the westernmost and west-central areas have been the traditional homeland of muslim filipinos since the 15th century, even before the arrival of the spanish, who began to colonize most of the philippines in 1565. majority of mindanao was the homeland of indigenous lumad groups, who were neither christians nor muslims.