Political history of Sri Aurobindo
Anushilan Samiti was founded as an attempt to organize Bengali youth through a program of physical fitness and spiritual training for a nationalist program. 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 Bengali lady by the name of Sarala Devi, and a third one led by Aurobindo Ghosh. The Anushilan Samiti had Aurobindo and Deshabandhu Chittaranjan Das as the vice-presidents, Suren Tagore the treasurer. Jatindra Nath Banerjee (Niralamba Swami), Bagha Jatin, Bhupendra Nath Datta (Swami Vivekananda's brother), Barindra Ghosh were among other initial leaders.
By 1905, the work of Aurobindo and his brother Barin Ghosh allowed Anushilan Samity to spread through Bengal.
History of the Anushilan Samiti
Western Anushilan Samiti in the aftermath of Manicktala Conspiracy found more prominent leader in Jatindra Nath Mukherjee which emerged distinctly as the "Jugantar group". Meanwhile, Rash Behari Bose extended the groups reach into north India, where he found work in the Indian Forest Institute in Dehra Dun. Mukherjee took over the leadership of the secret society to be known as the Jugantar Party. He revitalised the links between the central organisation in Calcutta and its several branches spread all over Bengal, Bihar, Orissa and several places in U.P., and opened hideouts in the Sunderbans for members who had gone underground The group slowly reorganised guided by Mukherjee's efforts, aided by an emerging leadership which included Amarendra Chatterjee, Naren Bhattacharya and other younger leaders. Some of its younger members including Taraknath Das left India. Through the next two years, the organisation operated under the covers of two seemingly detached organisations, "Sramajeebi Samabaya" (The Labourer's cooperative) and Harry & Sons. At around this time, Jatin began attempts to establish contacts with the 10th Jat Regiment then garrisoned at Fort William in Calcutta. Narendra Nath carried out through this time a number of robberies to obtain funds. In the meantime, However, a second blow came in 1910 when Shamsul Alam, a Bengal Police officer then preparing a conspiracy case against the group, was assassinated by an associate of Jatindranath by the name of Biren Dutta Gupta. The assassination led to the arrests which ultimately precipitated the Howrah-Sibpur Conspiracy Case.