The ‘character’ of democracy is regularly summarised using political-institutional measures of, for instance, ‘consensus’ or ‘majoritarian’ democracy. Yet, there is little quantitative-comparative research on the origins of such configurations. Drawing on literature on endogenous institutions and constitutional design, this article proposes a model for the explanation of empirical patterns of democracy. Using a novel database of 26 continental (neighbouring) European democracies and Bayesian spatial modelling, the results indicate that while today's empirical patterns of democracy in terms of proportional power diffusion can be traced back to waves of democratisation rather than historical partisan power configurations, decentral power diffusion can partially be explained by socio-structural factors, and spatial dependencies exist for all variants of power diffusion.