The Covenant of Water takes place from 1900 to 1977, spanning a time that witnesses significant change in Indian society. The story is set primarily in the southern Indian state of Kerala, and it reveals how the rigid caste system and the oppression of British imperialism impact India and its citizens. In addition, the novel focuses on a particular group of Indians: The Saint Thomas Christian community, a much smaller ethno-religious group than the Hindus and Muslims that occupy the Indian subcontinent. They identify as Malayalis and speak their own distinct language. While this group has its own traditions and religious practices, it also shares some features with India as a whole; members of this community adhered to the caste system at least until the latter part of the 20th century—The Injustice of Caste and Class is a theme explored throughout the novel. Like all Indians, the Saint Thomas Christians are also subject to the oppression of British until Independence gains its Independence in 1947.

The conversion of the Saint Thomas Christian community was likely the result of contact with European explorers who went East looking for spices beginning in the Middle Ages. However, as Abraham Verghese recounts in the novel, “Legend has it that Saint Thomas [one of Christ’s disciples] arrived in 52 AD, disembarking close to present-day Cochin” (15).