The historical roots of the Brahmo Samaj lie in the religious and intellectual ferment of early nineteenth‑century Bengal, under British colonial rule. In this milieu, Raja Ram Mohan Roy emerged as a central figure, seeking to respond both to entrenched orthodox Hindu practices and to the vigorous critiques of Christian missionaries. His earlier initiative, the Atmiya Sabha in Calcutta, served as a forum for monotheistic worship and discussion, and prepared the ground for a more organized movement. This search for a purified, rational faith found institutional expression when he founded the Brahma Sabha in Calcutta in 1828, a body that soon came to be known as the Brahmo Samaj.

The Brahmo Samaj thus originated as a reformist current within the broad Hindu tradition, emphasizing the worship of a single, formless God and rejecting idolatry, rigid caste distinctions, and practices such as sati. Its founder drew deeply on the Upanishads and Vedantic thought, interpreting them as affirmations of an eternal, singular divine reality, while also engaging with Islamic monotheism, Christian Unitarian ideas, and the rational spirit associated with Enlightenment thought. The movement’s early character was marked by a concern for ethical living and social reform, coupled with a desire to return to what was perceived as the monotheistic core of Hindu scripture. In this way, the Brahmo Samaj arose as a conscious effort to shape a religious life grounded in reason, ethical responsibility, and devotion to one supreme, unsearchable, immutable Being.