Jawarharlal Nehru, in his book, The Discovery of India, talks about his extensive tours of British occupied India in 1936 - 37. He mentions the major rivers, Sarnath, the Asoka Pillar, Fatehpur Sikri and the Indus Valley Civilization.
Primitive man used stone weapons and tools, hunted in groups and shared food. He later began to farm in river basins and trade. The Indus Valley Civilization flourished from 2500 to 1900 BCE and then declined in the next 300 years.
The Aryans entered India through the Indus Valley settlements between 2000 and 1000 BCE. These vedic people were warriors, farmed only a little and relied more on pasturing cattle. The Vedas and Avesta arose from a common pool of thought.
Nehru describes the formation of caste system in Later Rigvedic period. The working of the system is attempted to be explained through 3 stories: Shambhuk, Eklavya and the Son of Three Fathers.
Mahabharata occurred in 850 BCE and was written in 100,000 verses (shlokas) much later. Land became property then, but patriarchy was not yet fully rooted. Yudhisthir gambled everything and war became inevitable after his 13-year exile.
The Pandavas defeat the Kauravas in battle. Later, a centralized state administration, a tax system and a regular army were introduced. Property rights became paramount. Bhisma expounds wisdom on his death bed, titled as Shanti Parv.
The earliest play on Ramayan was called 'Pratima Natakam', written by poet Bhas around 200 BCE. Valmiki's Ramayan came later. While in exile for 14 years, Sita urges Ram to not fight the forest tribes who oppose saints living there.