Dabendranath Data, who came later to be called as 'Swami Vivekananda' after becoming a monk, was born on 12 January, 1863 in Kolkata. He had his early education and later his B.A. degree from Kolkata University.
From his childhood, Vivekananda was eager to see God face to face. He became a disciple of the great saint Ramakrishna Paramahansa of Dakshineswar temple, who taught him that God lives in every living creature. So, by serving them, one can serve God.
After his preceptor's death, Vivekananda established the Ramakrishna Mission which is still engaged in social service to the poor and the distressed, irrespective of caste, creed and religion.
Vivekananda went to America to participate in the Parliament of Religions held in Chicago in 1893. In his lengthy speech there, he explained that God is one and that the different religions are the different streams to terminate in one ocean, the God. His speech was highly applauded. Many Europeans became his followers.
Vivekananda taught his countrymen, through his writings and speeches, the essence of nationalism. He passed away in 1902.