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.
Anushilan Samiti
Resurgence of radical nationalism linked to the "Samiti" after the 1922s led to the passage of the Bengal Criminal Law Amendment Ordinance in 1924. This was enshrined as an act the following year. The act re-introduced extraordinary powers of detention to the police, and by 1927 more than 200 suspects had been imprisoned under the act, including Subhas Chandra Bose. The implementation of the act successfully curtailed a resurgence in nationalist violence in Bengal, at the time that the Hindustan Republican Association was rising in the United Provinces.