Did Hinduism reinforce the caste system in Ancient India?

Caste system didn't immediately exist in ancient India since rise of Sanatan Dharma or (Hinduism in Persian) in ancient Vedic civilization in 8000 BC.During this period there were only the Sages(godmen or Brahmins) and Kshatriyas (warrior cl).It came a little bit later than that say around 4000 BC. During this period significance of caste was only based on the respective professions of the people nothing else.It had nothing to do with the incarnation thing.There used to be no mistreatment of anyone on the basis of their castes or anything like that.The Brahmins during the Ramayana and Mahabharata period were simply the great sages who were always helpful to everyone irrespective of their castes. It only started getting misused by Brahmins much later around the period of 2000-1000 BC to claim their supremacy.At the same time it was more promoted during British Colonial rule for gaining political benefits.