Census that collected data on the social-hierarchy of caste was done…

NCERT (2025-26): “Colonialism and Caste … But by far the most important official effort to collect information on caste was through the census. First begun in the 1860s, the census became a regular ten-yearly exercise conducted by the British Indian government from 1881 onwards. The 1901 Census under the direction of Herbert Risley was particularly important as it sought to collect information on the social hierarchy of caste – i.e., the social order of precedence in particular regions, as to the position of each caste in the rank order.…”