Real name Iswarchandra Bandyopadhyaya. The title "Vidyasagar" which means 'ocean of knowledge', was given to him as an honor of excellence. But his contribution to the Bengali society is far more than just scholastic. Vidyasagar picked up the social reform work where Rammohan left it. He laid the foundation of modern Bengali language.

Vidyasagar was born on 26th September, 1820 in a village named Birshingha in Midnapore district to father Thakurdas Bandyopadhyay and mother Bhagavati Devi. He spent his childhood in extreme poverty. At the age of eight he came to Calcutta with his father where Thakurdas took book keeping job. The saying is that Vidyasagar learned English numbers by following the mile stones labels on his way to Calcutta.

In 1829, he got admitted to Sanskrit College. His concentration and quest for knowledge was so intense that he was used to study on street light as his family couldn't afford gas lamp at home. In 1839, he passed Hindu Law Examination and was honored with the title 'Vidyasagar'. Started his first job as the Chief Pundit in Fort William College, Calcutta in 1841 at the age of 20. Vidyasagar started learning English and Hindi here. In 1846, he joined Sanskrit College as Assistant Secretary. He wanted to improve the teaching system in the college and faced difference in opinion from then secretary Rasomoy Dutta. Vidyasagar left the job and joined Fort William College. In 1850, he became a Professor at Sanskrit College with one condition that he should be allowed to do the redesign of the education system. In 1851, he became the Principal of this college. None other than the Brahmins were allowed to study in Sanskrit College. He changed that rule and opened it for everybody.

Vidysagar realized that there was no place for education of women in the society. With his tireless effort to uplift the status of women in the society, he was able to establish some Girl's schools in different places of Bengal. But there was no good Bengali text book for basic Bengali education. He wrote Bengali books with basic language construct and fundamentals, like, "Barnaparichay", "Bodhoday", "Kathamala" etc. and then easy grammar books like "Upakramonika" and "Byakaron Kaumudi". He also introduced some basic books for Mathematical logic. Rabindranath Tagore called him as the father of modern Bengali language. Vidyasagar translated some masterpieces of Sanskrit and English literature into Bengali: "betaal panchabingshati"(Sanskrit Kathasarit sagar, "shakuntala", "bhranti bilaas" , "sitaar banabaas" and edited books like "raghubangsha", "kumarsambhab" etc.

Vidyasagar proposed the widow remarriage act in 1856. Widows could not marry again in those days. There was strong protest from the upper class and orthodox people of the society. He encouraged his son to get married to a widow. Sometimes, he spent money from himself to get widows married. He wanted to stop the Hindu men from getting married to many women. Not withstanding the miserable condition of Hindu widows, he introduced 'Hindu Family Annuity Fund'.

Vidyasagar opened as many as 1200 schools for women in those early days of women education. Vidyasagar was one of the founder member of University of Calcutta which was established in 1857. With help from some friends, in 1859 he established Calcutta Training School. This school was later named as Metropolition Institution and later was converted to a college named after him as Vidyasagar College.

Bold and articulate life style, honesty, strong determination, self respect, tenacity to fight against all odds - these charateristics made him a legendary personality in the era of Bengal renaissance. His strength of character became proverbial. He was also known for his charity and philanthropy and was called as "Daya-r sagar" - ocean of kindness. Renowned poet Michael Madhusudan Dutta wrote about him - "The genius and wisdom of an ancient sage, the energy of an Englishman and the heart of a Bengali mother". In 29th July, 1891, this great personality died.