From Empire of the Winds: The Global Role of Asia’s Great Archipelago, by Philip Bowring (I.B. Tauris, 2018), Kindle pp. 98-101:
Both Hindu and Buddhist beliefs benefited over time from gifts of land made by the pious. Gradually and with royal support temples and communities of monks and priests expanded and became centres of crafts and religious art. However, adoption of Indian ideas remained selective. For instance, though societies became more hierarchical as wealth and sophistication increased, the Indian caste system was not followed. Throughout the region women played a more active role in economic life – as they still do – than in India. Balinese Hinduism always displayed different characteristics from that of India as the imported religion adjusted itself to fit existing beliefs and practices. Nusantaria borrowed writing and many words, but imported languages never supplanted the various Austronesian tongues.
Despite the rise of direct links to Java and Sumatra from India and China, the isthmus trade remained important, providing links between eastern India and the Mon, Siamese and Khmer mainland. Trade also brought Buddhism, which made inroads in competition with both Hinduism and older beliefs, though both were probably still confined to the courts and surrounding townships. Buddhism was also spurring pilgrims and missionaries to travel on merchant ships.
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Elsewhere, too, the adoption of Indian ideas was selective rather than wholesale. While writing systems were borrowed and Indian languages used for the earliest local writing, the languages both of the court and the common people remained the local Austronesian or Khmer ones. Sanskrit for a while may have served the same priestly and official role as Latin in medieval Europe. But in time Indian Pallawa script was used to write local languages, the oldest found so far being in old Malay dating to the seventh century in Sumatra. The following century saw the development of Kawi script, derived from Pallawa but used to write old Javanese.
This script became the basis for other scripts including later Javanese and Balinese, which are still in use today. The first writing in Khmer also dates to the seventh century and uses an adaptation of Pallawa script. Six hundred years later this became the basis of Thai writing. The origin of Indian language influence also varied. Only Sanskrit words, those of religious and classical texts, not Prakrit or other common Indian speech, entered early writing in Java, but Tamil ones appeared in Sumatra. Despite the import of Indian religions, social structures appear to have remained indigenous. The maritime cultures borrowed Indian ideas in art and architecture but then adapted them so that they have distinctive aspects which are readily recognizable.
Apart from religion and script, the biggest influence was on legal and governance issues. The Indian text on statecraft, Arthashastra, and the ancient Brahman legal code, Manusmriti, were widely studied by ruling elites and had a major influence on the development of state systems. The Arthashastra, written in the fourth century BCE during the north India-based Maurya empire, which supposedly followed the peace-loving Jain religion, required rulers to be ruthless in protecting the interests of the state but disciplined, hardworking and learned. It was a secular recipe for enlightened despotism applicable to rulers of any faith. The Hindu notion of divine kingship was especially attractive to rulers, seeming to make the exercise of power something higher than mere personal leadership: a mandate from above. Buddhism on the other hand (and also Jainism) was more sympathetic to merchant interests and the accumulation of wealth. Its practitioners were also less constrained by caste issues and religious rituals, which for the devout were an obstacle to long sea journeys.


