Migration and settlement of mercantile communities have historically shaped the socio-economic landscape of frontier regions, and the Brahmaputra Valley of Assam offers a particularly instructive case in the long-distance migration of the Marwari trading community from Rajasthan. This paper examines the historical trajectory, socio-economic integration, and cultural assimilation of Marwaris in Assam, with focused attention on three significant trade hubs: Fancy Bazaar in Guwahati, Sivasagar and Tinsukia. Beginning with the precolonial and colonial antecedents of Marwari mobility eastward, the study traces how members of this community established themselves as moneylenders, shopkeepers, and wholesale traders under the patronage of the East India Company and the expanding tea economy, and how, over successive generations, many Marwari families assimilated linguistically, culturally, and socially into Assamese society while retaining distinctive communal and commercial identities. The paper situates Fancy Bazaar's transformation from a colonial execution ground and jail precinct historically called ‘Phansi Bazaar’( NTাঁdT R5Tৰ ) into Guwahati's foremost commercial district as a microcosm of this broader process of spatial and economic transformation. A mixed-methods research design combining archival analysis, structured surveys, and key-informant interviews is proposed and partially illustrated to assess patterns of language adoption, intermarriage, festival participation, business networks, and civic engagement among Marwari residents of the three study sites. Findings indicate considerable variation in the depth of assimilation across locations, shaped by the duration of settlement, generational distance from the original migrants, and the density of local Assamese social networks. The study concludes by reflecting on the broader implications of these findings for understanding diaspora integration in Northeast India and offers directions for further empirical research.

Keywords: Marwari community, Assam, migration, socio-economic integration, cultural assimilation, Fancy Bazaar, Guwahati, Sivasagar, Tinsukia, diaspora studies, Northeast India.