Complex sentence: The rise of historical pre-Islamic Malay kingdoms and later Islamic sultanates assimilated most of the historical Orang Asli people into their community, being effectively Malayalised and become the ancient ancestors for many present-day Malay people.
Split into simpler sentences: The rise of historical pre-Islamic Malay kingdoms and later Islamic sultanates assimilated and Malayalised most of the historical Orang Asli people into their community. They become the ancient ancestors for many present-day Malay people.