Using objective measures of lung function, we document strong positive associations in health within couples in all European countries but large and significant differences in this correlation within broad European regions, with Southern Europe having by far stronger correlations than elsewhere. We analyze potential explanations for such differences, investigating the role of measures capturing current and past health behaviors, early life circumstances of each spouse, and measures capturing assortative mating in multiple dimensions. We show that marital sorting patterns by dimensions of early life health and socioeconomic position, as well as by geographical subregion within countries, are key to understanding the empirical patterns observed.