Church construction was one of the most challenging, and most political, tasks undertaken by medieval cities. Comparing examples from across Europe reveals profound differences, however, in both the architecture of politics and the politics of architecture; that is, how building projects were administered and how their administration shaped their socio-political significance. Although ranging across the continent, this article is centered on construction in two representative cities: Vienna and London. While the former had a small number of churches, all under the direct control of the mayor and council, the latter had over a hundred, each overseen by locally appointed officers. In Vienna, church construction was, thus, an important field of activity for the city government, which oversaw the work and celebrated its own leadership of the project; in London, it lay outside civic control and offered local opportunities for domination by wealthy families. This difference can be found across the continent, separating the large, old cities of England, northern France, Spain, and the Low Countries, which could have numerous churches, from smaller towns and cities both in these places and across the rest of central, northern, and southern Europe, which typically had a single, major parish church and only a few subordinate ones. This article considers the implications of these two contrasting models—centralized and decentralized, civic and parochial, high government and local politics—on how architectural production functioned as a field of political activity and how church building shaped local distributions and articulations of power in medieval Europe.