Population development and burial practices in the Hungarian Middle Ages: paleodemographic insights into the adoption of Christianity

This study examines population development and changing mortuary practices in the Carpathian Basin between the 7^th and 13^th centuries CE, focusing on the demographic and symbolic implications of subadult burial patterns. Life expectancy at birth (ex°), defined here as an archaeological demographic proxy rather than a direct indicator of biological lifespan, was calculated or reconstructed for 23 medieval cemeteries (N = 3,602 individuals), based on osteologically estimated age-at-death data. Using hierarchical cluster analysis (UPGMA), linear discriminant analysis (LDA), and subadult representation (ages 014 years), we identified two major temporal clusters: one comprising 7^th10^th century sites and another spanning the 11^th13^th centuries. A significant decrease in ex° values in the later cluster (mean = 28.6 years) compared to the earlier one (mean = 33.2 years), coupled with a higher proportion of child burials (36.2% vs. 25.0%), suggests that Christianization led to increased mortuary inclusion of children. The LDA model confirmed that ex° values moderately distinguished between archaeological periods (56.5% classification accuracy). These patterns reflect not only biological mortality but also cultural shifts in the perceived personhood and spiritual status of children, as Christian norms redefined the moral community of the dead. Our results demonstrate that paleodemographic indicators such as life expectancy can provide insight into broader ideological transformations in medieval Central Europe.