How was buddhism a reaction to the vedic beliefs and rituals that dominates south asia?

The Vedic beliefs of South Asia had a very well defined Caste System.

There were the Upper classes, also known as the Brahamins or the priests, there were the Business Class, the Soldiers and the labour class and at the bottom were the lowest of the low castes, known as the untouchables.

This system believed that everyone is born into a caste system and you cannot 'escape' or dissociate yourself from it.

There was a huge divide between the rich and poor.

Bhuddha saw this as an unjust society and his beliefs were based on the principles of equality and brotherhood.