By 1000 BC, the inhabitants of the Philippine archipelago had developed into four distinct kinds of peoples: tribal groups, such as the Aetas, Hanunoo, Ilongots and the Mangyan who depended on hunter-gathering and were concentrated in forests; warrior societies, such as the Isneg and Kalinga who practiced social ranking and ritualized warfare and roamed the plains; the petty plutocracy of the Ifugao Cordillera Highlanders, who occupied the mountain ranges of Luzon; and the harbor principalities of the estuarine civilizations that grew along rivers and seashores while participating in trans-island maritime trade.
Around 300–700 AD, the seafaring peoples of the islands traveling in balangays began to trade with the Indianized kingdoms in the Malay Archipelago and the nearby East Asian principalities, adopting influences from both Buddhism and Hinduism.
The Philippine–American War ensued, with extensive damage and death, and ultimately resulting in the defeat of the Philippine Republic.
In 1972, Philippine President Ferdinand Marcos imposed martial law.
Scholars generally believe that these social groups eventually developed into various settlements or polities with varying degrees of economic specialization, social stratification, and political organization.