Political activities began taking an organised form in Bengal at the beginning of the 20th century. By 1902, Calcutta had three societies working under the umbrella of Anushilan Samity, a society earlier founded by a Calcutta barrister by the name of Pramatha Mitra. These included Mitra's own group, another led by a Bengalee lady by the name of Sarala Devi, and a third one led by Aurobindo Ghosh- one of the strongest proponents of militant nationalism of the time. The Anushilan Samiti had Sri Aurobindo and Deshabandhu Chittaranjan Das as the vice-presidents, Suren Tagore the treasurer. Jatindra Nath Banerjee (Niralamba Swami), Jatindra Nath Mukherjee (Bagha Jatin), Bhupendra Nath Datta (Swami Vivekananda's brother), Barindra Ghosh younger brother of Aurobindo Ghose, were among other initial leaders. By 1906, the works of Aurobindo and his brother Barindra Ghosh allowed Anushilan Samity to spread through Bengal. The controversial 1905 partition of Bengal had a widespread political impact: it stimulated radical nationalist sentiments in the Bhadralok community in Bengal, and helped Anushilan acquire a support base amongst of educated, politically conscious and disaffected young in local youth societies of Bengal. The Dhaka branch of the Anushilan Samiti was formed by Pulin Behari Das, who was once a teacher in the Dhaka Government College and, later, a founding headmaster of 'National School' (Dhaka), along with his followers, in 1906. He, like Barindra Ghosh, believed in a highly centralised one-leader organisation. Under their leadership, respectively in Dhaka and elsewhere, in a spirit of a boastful showdown, Anushilan Samiti slowly adopted untimely terrorism programmes during the first decade of 20th century, with 1905 Partition of Bengal acting as a major catalyst. The Dhaka branch of Anushilan was led by Pulin Behari Das and spread branches through East Bengal and Assam. Aurobindo and Bipin Chandra Pal, a Bengali politician, began in 1907 the radical Bengali nationalist publication of Jugantar (Lit:Change), and its English counterpart Bande Mataram. Among the early recruits who emerged noted leaders where Rash Behari Bose, Jatindranath Mukherjee, and Jadugopal Mukherjeehad branches all over Bengal and also other parts of India.
Satish Chandra Basu was a student of General Assembly Institution ( At present Scottish Church College). Gourhari Mukherjee established an Excercise Club for the students. Satish Chandra was one of the members of the club. He selected a place for excercise in the college compound. As a result he secured strong hold amongst the students. That was in the year 1901. Which was ultimately converted to Anushilan Samity. The word " Anushilan" had been coined from the novel of Bankim Chandra.
In 1902, 24th March Anushilan Samity was formally inaugurated in Calcutta at a meeting presided over by Pramatha Nath Mitra. He became the first president of the organisation.'
In 21 Madan Mitra Lane, there was an Excercise Club of the Samity and its office was in a house near its excercise club. In 1905, office was shifted to 49 Cornwllis Street, Calcutta.