John Graunt (1620-1674) was one of the first demographers in England. Though by profession he was a haberdasher, Graunt made significant contributions to early statistics and census methods through his analysis of mortality records in London. His most notable work, Natural and Political Observations Made upon the Bills of Mortality, was one of the first to use statistical analysis and helped estimate London's population size. Graunt's work helped establish the fields of medical statistics and demography, leading to major advances in public health. He made important contributions despite not having a formal background, and was respected for his peacemaking and involvement in various civic roles in London.