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
Anushilan and Jugantar each were organised on different lines, reflecting their divergence. "Anushilan Samiti" was centrally organised, with a rigid discipline and vertical hierarchy. Jugantar, was more loosely organised as an alliance of groups, acting under local leaders that occasionally coordinated their actions together. The prototype of Jugantar's organisation was Barin Ghosh's organisation set up in 1907, in the run-up to the Manicktolla conspiracy. It sought to emulate the model of Russian revolutionaries that was described by Frost. The regulations of the central Dhaka organization of the "Anushilan Samiti" were written down, and reproduced and summarised in government reports. According to one estimate, the Dacca Anushilan Samiti had at one point 500 branches, mostly in the eastern districts of Bengal, with 20,000 members. Branches were opened later in the western districts, Bihar, and the United Provinces. Shelters for absconders were established in Assam and in two farms in Tripura. Organisational documents shows a primary division between, on the one hand the two active leadersBarin Ghosh and Upendranath Bannerjee, and the rank-and-file on the other. Higher leaders including Aurobindo were supposed to be known only to the active leaders. Erstwhile members of "Anushilan", particularly those of the Maniktala group, had suggested that the each group were interconnected with a vast web of secret societies throughout British India. However historian Peter Heehs concludes the links between provinces were limited to contacts between a few individuals like Aurobindo who was familiar with leaders and movements in Western India. He concludes the Maniktala society had links between the other groups and the Manicktalla society, such as the Anushilan and Atmannati Samitis, were more often competitive than co-operative. An internal circular of circa 1908 written by Pulin Behari Das, describes the division of the organisation in Bengal, which largely followed British administrative divisions, with central "Samitis" linked with a few small Samitis.