[3] Born on 4 November 1871 to Purna Chandra Roy, a member of the Bengal Judicial Service, in a village in Khulna district (now in Bangladesh), young Sarat came in contact with tribal people after his father was posted in Purulia.

He left teaching and started practicing as a lawyer and became a pleader in the district court in the 24 Parganas in Calcutta in 1897.

[4] His interest into the plight of the "tribal" people developed in the course of his visits as a lawyer, in the interior areas of the Chota Nagpur Division.

He was deeply moved by the plight of the Munda, Oraon and other tribal groups, who were subjected to the continued oppression by an apathetic colonial administration, and by a general contempt towards them in courts of law, as "upper-caste" Hindu lawyers had little knowledge of their customs, religions, customary laws and languages.

Keeping all this in perspective, he decided to spend years and decades among tribal folks to study their languages, conduct ethnography, and interpret their customs, practices, religion and laws for the benefit of humanity, and also for the established system of colonial civil jurisprudence.