The volume, Who were the Shudras? by Ambedkar is one of the most popular sociological works on the Indian caste system. This is a study based on Ambedkar's hypothesis on the formation of Shudra varna or caste in the chaturvarna (four classes) order in the Indian caste system. He explains of how the Shudra caste became so degraded. He gave his exposition about the Shudra based on the references taken from the ancient Sanskrit canons like Vedas, Epics like Mahabharata, etc.