Around the year 1500 B.C. a group of people from Central Asia, (modern day Russia) began to settle in the Indus Valley. These people were nomads who rode horses and raised livestock . They were proud, fierce, and deeply religious. As they settled in, they began to grow crops. People started to have occupations.
In each tribe, people belonged to a group. In the beginning these were just occupations. You could move fromone group to another group. This changed over time, until a person’s occupation or group depended on birth. If your father was a farmer, you had to be a farmer. Changing from one group to another became very difficult.
Five rigid social classes evolved from this. They were Brahmin, Kshatriya, Vaishya, Sudra or Shudra, Untouchable or Dalit (Pariahs) .