The pro-European policy of the Siamese government of King Narai in the second half of the seventeenth century and the aggressive approach of France which, meeting the Siamese foreign policy, commercially as well as religiously advanced into Siam and even sent a military unit to this kingdom, gave rise to a strong antipathy and opposition among the Siamese bureaucracy and the Buddhist population. The antipathy of the Siamese society manifested in the 1688 Palace Revolution led by Phettharacha who was backed by the confidence of the Buddhist population and a large part of the bureaucracy. The revolt of the Makassarese during August and September in 1686 occurred also as an opposition to the pro-European and Catholic-friendly policy of the Narai court. The Makassar revolt ended, however, in failure, while the revolution in 1688 was successful, bringing forth a new regime of the so-called Ban Phlu Luang dynasty. A plain and obvious reason of the failure was that King Narai was still maintaining a strong control over the court and the population. Another important reason seems to lie in the difference of attitude of the Siamese society toward the two events. To put it simply, while the Siamese society gave support to the 1688 revolution, it did not sympathize with the Makassar revolt and even regarded it as dangerous. The reasons of such a point of view and attitude toward the Makassar revolt might have been that the actors of the event were not the Buddhist Thai who constituted the main group of the Siamese population, but Makassar Muslims from Sulawesi, Indonesia. This study shows that the Siamese society then regarded Buddhism as the cultural fundament of the Siamese kingdom, with the king and the kingship being essentially Buddhist. Although the Siamese society, which attached great importance to overseas trade, attracted Muslims and Christian Europeans into the kingdom, allowing them relatively free economic and cultural activity, it did not look on unconcernedly when they threatened the Siamese cultural tradition and the Buddhist cultural essence of the Siamese kingship, the protector of that tradition.