History of the Anushilan Samiti
Around 1902, Aurobindo Ghosh arranged for Bannerjee to return to Calcutta to begin organisational work, where he began a gymnasium and a youth society. It was at this time that Bannerjee came in touch with Vibhuti Bhushan Bhattacharya, Sarala Devi Ghoshal and Pramathanath Mitra. In Calcutta, a few clubs and societies were still active at the time. Most notable was a gymnasium in Ballygunge Circular Road run by Sarala Devi herself, a second was an organisation named "Anushilan Samiti" founded by Satish Chandra Basu with the patronage of Pramathanath Mitra. A third one was a youth club called "Attōnnōti Samiti" (Self-improvement society) in central Calcutta.
Jugantar
Jugantar or Yugantar ( "Jugantor") (English meaning "New Era" or more literally "Transition of an Epoch") was one of the two main secret revolutionary trends operating in Bengal for Indian independence. This association, like Anushilan Samiti started in the guise of suburban fitness club. Several Jugantar members were arrested, hanged, or deported for life to the Cellular Jail in Andaman. Thanks to the amnesty after World War I, most of them were released and could give a new turn to their political career, mainly: (a) by joining Deshbandhu's Swarajya or (b) the Communist Party of India; or (c) M. N. Roy's Radical Democratic Party; or (d) later Subhas Chandra Bose's Forward Bloc in the 1930s.This party was established by leaders like Aurobindo Ghosh, his brother Barin Ghosh, Bhupendranath Datta, Raja Subodh Mallik in April 1906. Barin Ghosh and Bagha Jatin were the main leaders. Along with 21 revolutionaries, they started to collect arms, explosives and manufactured bombs. The headquarters of Jugantar was located at 27 Kanai Dhar Lane, then 41 Champatola 1st Lane, Kolkata.