The study discusses the early history of the province until the end of the Spanish rule in the Philippines with concentration on the changes in the political and social milieu of the Maguindanao would as a result of the Spanish incussion into the valley. The findings center on the physical description of the region, its people, and the three important institutions, the social, political, and economic institutions which underwent some degree of changes as a result of the Spanish occupation in the Philippines. It further describes the beginning of the Spanish attempt to colonize the valley in 1578 with the Maguindanaons and their struggles against the Spaniards and other developments that took place in the area.