Migration and the mixing of language and cultures thru interactions and connections changed ethnic identities. Social developments occurred on several levels. Culturally distinct settlements started to emerge with the migration of the Vedic people and with the Vedic people came the caste system.
Brahmin priests sought to secure relationships with kings as castes mixed indiscriminately. They wanted the kings (Raja’s) to be viewed as a divine power; this was accomplished with a ritual being performed by the Brahmins priests.
A caste divine of society based on both occupation and family lineage. The Hindu caste system divisions are as follows: Brahmins-priests, Kshatriyas-warriors, Vaishyas-merchants & peasants, Shudrus-laborers, Chandalas-the impure. Caste rules were enforced by both political and religious authorities and marriage outside your caste was prohibited. By combining the caste system and the belief in Karma, ancient law makers could expect people to follow the rules of the caste.
Buddhism rejected the caste system. Siddhartha Gautama, the enlightened one (Buddha) believed that the path to enlightenment was to abandon all worldly desires, of course the oppressed lower castes believed and followed his teachings.
Buddhism-is non-theistic, it is about controlling ones desires, mindfulness, gaining wisdom, being ethical, devotion and mental discipline (often thru meditation) the goal is finding “nirvana.”