Historical demography is the interdisciplinary academic field dedicated to the quantitative and qualitative study of human populations in the past. It employs historical sources such as census records, parish registers, genealogies, and administrative documents to reconstruct and analyze demographic processes, including fertility, mortality, migration, marriage, and family structure, across different periods and regions. The field is characterized by its reliance on historical data, often fragmented or incomplete, and its application of demographic methods to historical contexts, providing crucial insights into long-term societal changes, the impact of historical events on populations, and the historical roots of contemporary demographic patterns.