Most anthropological studies during the last several decades have tended to be cross-sections of a particular society at one point in time. Historical materials in anthropological reports were consciously or unconsciously ignored because it was considered unimportant to the theoretical framework (due to the influence of the structural-functional approach in anthropology). However, the absence of historical depth in anthropological writings has been lamented by many anthropologists and particularly by Evans-Pritchard (1950) who aptly describes the need for using the historical material in anthropology. Whilst the author's interest in this paper is not purely historical, but he thought historical materials necessary to deal with change over time and hence to understand the past economic development and present political structure of Nepal more clearly. This paper focuses on a historical approach to understanding the past economic development and also present socio-economic situations of the Nepal Terai, with special reference to Indian migration in the area.