Raja Rammohan roy was one of the greatest social and religious reformer of the 19th century. This great personality was born on 1772 in Bengal.
In 1828, he founded the Brahmo sabha, which he latter renamed, brahmo samaj. The brahmo samaj believed in Monothesm or worship of one god.
Raja Rammohan Roy was against the rigidity of the caste system. He started a campaign for the abolition of sati and purdah system, condemned polygamy, discouraged child marriges and advocated the right of widows to remarry. It was because of his efforts that, william benthik, the governal general of Indai, passed a law in 1821 making the practice of sati illegal and punisheble by law. He also protested against restrictions on the freedom of press.
hope it helsp.. :)