'Nildarpan' or the 'Indigo Planting Mirror', a play on the Bengal indigo plantation written by Dinabandhu Mitra, was first performed on 7 December 1872 in Jorasanko, West Bengal. The play evoked the cruelties of the planters towards their workers and was not given a hearty welcome by the British. Indigo, the blue dye, was an extraordinarily profitable product in the 19th century, after much of the industry had shifted from the Caribbean to Asia. The Bengal indigo production was embedded in a rural society that had long known seasonal labour migration. Rural labour migrants were willing to work for extremely low pay.
Willem van Schendel provides a vivid description of the harsh working conditions involved in indigo production In 'Working for Wages in Colonial Bengal's Indigo Industry' in: Marcel van der Linden and Leo Lucassen (ed.), Working on Labor: Essays in Honor of Jan Lucassen (Leiden and Boston: Brill, 2012), 47-73.