Political maps and cultural territories

The international boundary between India and Bangladesh came into being in 1947, but some of its segments have much older histories. The oldest segment lies below the mountains of Meghalaya and forms the northern border of the Sunamganj Zila of Bangladesh. This boundary runs east and west, cutting across many short rivers, whose names elude most maps, one being the Dhamalia river, which falls from Pandua, in India, and empties into the Surma River, near the town of Sunamganj, in Bangladesh. Borderlands of Mughal Bengal had once spanned the basins of the Dhamalia and other parallel rivers draining the mountains into plains below, but a definite geographical divide emerged in 1790, in the Sylhet district of British Bengal, in the form of a boundary line that served explicitly to restrict and regulate mobility between two political territories, defined as the homelands of two distinct cultures in the mountains and plains, respectively.

The rationale for inventing this boundary was an early precursor of the "two nation theory," which eventually informed the partition of British India. At the same time, the birth of this boundary indicates that international borders are not homogenous, despite their appearance on maps as continuous lines. In addition, the local history of this boundary evokes many others in the old borderlands of mountains and plains spanning India's northeast and Bangladesh, where state borders today have meanings quite distinct from the meanings enshrined in international law and in national sentiments.