1-The Harappa civilization declined
Hinduism starts to develop aroud 2600 BC.
The Harappan Civilization occurred in Indus Valley around 2600 – 1900 BC, the area where is today Pakistan and India.
From 1800 BC to 1700 BC the Harappa civilization declined, the reason is still unknown.
2 Society was divided into four varnas.
Around 1600 BC began the Aryan invasion in Indus River Valley. They brought the Sanskrit language.
In 1500 BC the Vedic Ages begins with the writing scriptures of Hinduism, the Vedas.
The varnas have been known from the hymns in Rig Veda.
The society is divided by four caste: Brahamin, Kshatriya, Vaishya, Shudra.
3 A rigid caste system developed.
Around 900 BCE the caste was well established and no marriage was allowed between different varnas.
4 The Bhagavad Gita was written.
The Bhagavad Gita was written at some point between 400 BCE and 200 BCE.
