- The Indus Valley civilization emerged in the river valleys of the Indus River around 1500 BC and included major cities like Harappa and Mohenjo-Daro with populations of 35,000-40,000 people.
- Around 1500 BC, nomadic Aryan groups migrated into northern India and conquered the Indus Valley civilization, establishing new social divisions and institutions. They developed a caste system that stratified Hindu society into priests, warriors, commoners, peasants, and untouchables.
- Hinduism and Buddhism both originated in ancient India, with Hinduism believing in dharma, karma, samsara, and deities like Brahma and Shiva, while Buddhism rejected the Hindu caste system