A society founded in Bombay in 1875 by Dayānanda Sarasvatī to promote his version of reformed Hinduism. Through it he advocated what he saw as a return to a pure, Veda-based, pre-Mahābhārata war form of the religion, shorn of its Epic, Purāṇic, and devotional elements, and focused on an impersonal God. Dayānanda understood the Veda as containing the blueprint for all things, including apparently modern inventions. This combination of traditional authority and openness to technology appealed to members of the merchant castes in the Punjab and Northwest India, and it was here that the Ārya Samāj attained a significant following. Encouraged by this, Dayānanda moved the society's headquarters to (pre-Partition) Lahore.
From the outset Dayānanda's purpose was broadly political, in so far as he sought to counter the attacks made on Hinduism by Christian missionaries, to reconvert low-caste Indian Muslims and Christians, and to promote a national identity based on the Sanskritic tradition. His advocacy of radical social reforms, such as the availability of a traditional Vedic education for women and the low castes, an end to child and arranged marriages, and a reinterpretation of the caste system along meritocratic lines, was designed to further this reforming, neo-traditionalist agenda. Dayānanda's ultimate aim was Hindu unity in the face of the perceived threat of other religions, particularly Islam and Christianity. Many members of the Ārya Samāj subsequently took prominent roles in the nationalist movement, and in more recent times others have been closely associated with the various militant organizations dedicated to the establishment of a Hindu state.
After its founder's death, the Ārya Samāj split into two branches, one conservative and Sanskritic, the other aiming to provide a ‘progressive’, English-medium education in its schools and colleges. There are now ‘Dayānanda Anglo-Vedic’ (DAV) colleges in many Indian cities, as well as Ārya Samāj centres across India and abroad. Current membership of the society is claimed to be over one million.