Synopsis The Santal Insurrection of 1855-57 is an important episode in the annals of Bengal and Bihar during the mid-nineteenth century, which forms, in many ways, a transitional period in the history of India as a whole. Certain important original records had been discovered by author and utilised for a detailed and critical study of the subject in this thesis. He had often quoted extracts from the unpublished records, with a view to bringing these to light as far as possible.