Solution:

• Sachindra Nath Sanyal was an Indian revolutionary and a founder of the Hindustan Republican Association (HRA, which after 1928 became the Hindustan Socialist Republican Association) that was created to carry out armed resistance against the British Empire in India.

• Sanyal founded a branch of the Anushilan Samiti in Patna in 1913.He was extensively involved in the plans for the Ghadar conspiracy, and went underground after it was exposed in February 1915. He was a close associate of Rash Behari Bose. After Bose escaped to Japan, Sanyal was considered the most senior leader of India’s revolutionary movement.

• Sanyal was sentenced to life for his involvement in the conspiracy and was imprisoned at Cellular Jail in the Andaman and Nicobar Islands, where he wrote his book titled Bandi Jeevan (A Life of Captivity, 1922).