The entire China-India boundary has never been formally delimited by any mutually-accepted treaty. There has existed a boundary line of actual control between the two countries. It took shape on the basis of the extent of each other’s administra tive jurisdiction over a long course of time. India-Nepal relations have been framed and molded by their geological contiguity and socio-social characters which has affected their verifiable past. The recorded linkages radiating from the racial, religious and etymological affinities were conceivable in view of the 1,750-km-long open outskirt which made correspondence less demanding and conceivable. The intersection of the outskirt by the general population has not just affected each other’s history, society and custom additionally affected the political, monetary and vital relations between the two nations. China wants to invest in big connectivity projects in Nepal but prefers to bring its Asian competitor, India, on board. Some Nepali and Chinese scholars see this as an opportunity for trilateral cooperation between Nepal, India, and China, but Indian policymakers and academics have not shown much interest. The book examines the Indo-Nepal relations from a historical perspective and discusses that a part of the relation remains as a dark side, which has been less explored in the existing literature.