This short article analyses the historical context and process through which Nepalis, mainly from the central hill region, migrated to various frontiers, particularly, the northeast of India since the mid-19th century. The author highlights two key factors that influenced this trend: the economic and ecological crisis in the hills of Nepal, and the active recruitment of Nepalis by the British in its imperial army in India. He claims the economic and ecological crises to have risen from growing disintegration of land, indebtedness, mounting population pressure, lack of cultivable land, and chronic food deficit in the hill areas of central Nepal. The article claims how the Indo-Nepal Friendship Treaty of 1950, the Tripartite Delhi agreement of 1951, and the revised Indo-Nepal Agreement of 1956, only formalised a historical migratory trend that had already existed during the British period. 

Dutt, S. 1981. Economic and Political Weekly. 16:24, 1053-1055.