The imperative to produce proof of identity has shaped the very life-chances of people inhabiting the diverse geographies, socio-economic groups, and timescales of India and yet, a history of identification documents is nowhere on the horizon. How did the ration card, which went by different names such as the food card, the household consumer card, and more recently, the food security card, crystallize into proof of residence? After the Partition of India, how did the Indian state classify refugees as poor, displaced, and lower caste? Might there be alternative conceptualizations of the period corresponding to what has been regarded the vile and malignant ‘Licence Raj’ and the ‘Inspector Raj’? These questions are now more relevant than ever owing to the changes that the political and technological messiahs behind the Aadhaar have promised within the welfare landscapes of India. In attempting to illuminate the paper regimes of welfare that are now being radically transformed, the author deploys eclectic forms of ethnography and archival research to bring forth the historical quest for proof in the urban margins of India, and Delhi in particular. In Pursuit of Proof moves with methodological agility across moments as disparate as the Second World War, the Partition, ‘Licence Raj’, a forgotten but portentous enumeration initiative, and the production of a unique number. What, however, weaves this vast and ambitious narrative together is the book’s intricate and layered exposition of a state whose welfare capacities of governing are drawn from popular practices of knowledge around documenting and proving identities.