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
At least initially, membership was predominantly Hindus, which was ascribed to the religious oath of initiation and was unacceptable to Muslims. Each member was assigned to one or more of three roles. These included collection of funds, implementation of planned actions and propaganda respectively. In practice, however, the fundamental division was between what was conceived as "military’’ work and ‘‘civil’’ work. "Dal"s (teams) consisting of five or ten members led by a "dalpati" (teamleader) were grouped together in local "samiti"s led by "adhyakshas" (executive officer) and other officers. These reported to district officers appointed by and responsible to the central Dhaka organization. This was commanded by Pulin Das and those who succeeded him during his periods of imprisonment. "Samitis" were divided into four functional groups: violence, organisation, keepers of arms, householder department. Communications were by special couriers and were written in secret code. This practice and many others were taken from literary sources and were in part a concession to the young men’s need to act out romantic drama. Less is known about the "Jugantar" network, which took the place of the Maniktala society after Alipore Bomb case. It faced divisions similar to "Anushilan". Historian Leonard Gordon notes that at least in the period between 1910 and 1915, each group "dal" in the "Jugantar" network were separate units composed of a leader known as "dada" ("lit": elder brother), and his followers. The "dada" was also guru, tutoring those under his command, practical skills, revolutionary ideology and strategy. Gordon suggests that the dada system developed out of pre-existing social structures in rural Bengal. "Dada"s both co-operated and competed with each other for men, money and material.