The metatarsal of Callao Man is reported to have been reliably dated by uranium-series dating to 67,000 years ago thereby replacing the Tabon Man of Palawan, carbon-dated to around 24,000 years ago as the oldest human remains found in the archipelago. Negritos were among the archipelago's earliest inhabitants but their appearance in the Philippines has not been reliably dated. There are several opposing theories regarding the origins of ancient Filipinos. F. Landa Jocano theorizes that the ancestors of the Filipinos evolved locally. Wilhelm Solheim's Island Origin Theory postulates that the peopling of the archipelago transpired via trade networks originating in the antediluvian Sundaland area around 48000 to 5000 BCE rather than by wide-scale migration. The Austronesian Expansion Theory states that Malayo-Polynesians coming from Taiwan began migrating to the Philippines around 4000 BCE, displacing earlier arrivals. Whatever the case, by 1000 BCE the inhabitants of the archipelago had developed into four kinds of social groups: hunter-gathering tribes, warrior societies, petty plutocracies, and maritime-centered harbor principalities.
Trade between the maritime-oriented peoples and other Asian countries during the subsequent period brought influences from Hinduism, Buddhism, and Islam. During this time there was no unifying political state encompassing the entire Philippine Archipelago. Instead, the islands were divided among competing thalassocracies ruled by various datus, rajahs, or sultans. Among them were the kingdoms of Maynila, Namayan, and Tondo, the rajahnates of Butuan and Cebu, and the sultanates of Maguindanao and Sulu. Some of these societies were part of the Malayan empires of Srivijaya, Majapahit, and Brunei. Islam was brought to the Philippines by traders and proselytizers from Malaysia and Indonesia. By the 15th century, Islam was established in the Sulu Archipelago and