During colonial rule, numerous socio-religious movements emerged in India, primarily aiming to reform and synthesize Hinduism in response to Western influence, missionary activities, and internal social evils. Two prominent examples are the Brahmo Samaj and the Arya Samaj.

Brahmo Samaj: Founded by Raja Ram Mohan Roy in 1828, the Brahmo Samaj was a reformist movement that sought to purify Hinduism by advocating monotheism and rejecting idolatry, polytheism, and the caste system. It championed social reforms like the abolition of Sati, child marriage, and promoted women's education and widow remarriage. The movement drew inspiration from ancient Upanishadic philosophy while also incorporating rationalist and humanist ideas from Western thought, aiming to create a modern, ethical, and universal form of Hinduism. Its approach was intellectual and appealed mainly to the educated elite, laying the groundwork for subsequent social reform efforts.

Arya Samaj: Established by Swami Dayanand Saraswati in 1875, the Arya Samaj represented a more revivalist and militant reform movement. Its core objective was 'Back to the Vedas,' asserting the infallibility of Vedic knowledge and rejecting later Hindu scriptures, idolatry, and the caste system based on birth. It promoted monotheism, cow protection, and the 'Shuddhi' (purification) movement for reconversion to Hinduism. Unlike the Brahmo Samaj, the Arya Samaj was more assertive in defending Hinduism against external criticisms and internal decadence, fostering a sense of Hindu identity and pride. It had a significant impact in North India, contributing to social awakening and nationalist sentiments through its emphasis on self-reliance and Vedic values.