The earliest known surviving written record found in the Philippines is the Laguna Copperplate Inscription. By the 1300s, a number of the large coastal settlements had emerged as trading centers, and became the focal point of societal changes. Some polities had exchanges with other states across Asia. Trade with China is believed to have begun during the Tang dynasty, but grew more extensive during the Song dynasty. By the 2nd millennium CE, some Philippine polities sent delegations participating in the tributary system of China. Indian cultural traits, such as linguistic terms and religious practices, began to spread within the Philippines during the 10th century, likely via the Hindu Majapahit empire. By the 15th century, Islam was established in the Sulu Archipelago and spread from there.