A River Sutra mentions three major historical events from India’s past: the Indo-Aryan Migration beginning in 2,000 BCE, the Mughal Empire from 1526-1857, and the British Raj from 1858-1947. The novel takes place after the conclusion of the British Raj. The Indo-Aryan Migration was the movement of nomadic Aryan peoples from Central Asia into India, bringing different languages and cultures to existing pre-Aryan Indian cultures. In the novel, Dr. Mitra notes that the Narmada river is still a battleground between pre-Aryan and Aryan cultures; he associates pre-Aryan cultures with tribalism and Aryan cultures with rationalism. Many modern languages spoken in contemporary India and the surrounding regions come from the Indo-Aryan languages spoken by the Aryan peoples; also, though Sanskrit is no longer spoken as a language, it is intrinsic to Hinduism as a religion and came from the Indo-Aryan people.

The Mughal Empire was part of the Islamic conquest of India. It began with military conflicts with the existing governments in India in the 16th and 17th centuries. Though Islam did not become a majority religion in India, India does have a significant Muslim population. The novel makes references to Mughal architecture and reveals the lasting impact of Islam on Indian culture and religion.