Supported by a wide range of new and as yet unexplored data on each electoral district in 17 European countries, this long-term comparative analysis describes the territoriality of electoral participation and voting for political parties, along with how these have changed since the mid-nineteenth century, from highly territorialized policies to nationalized functional alignments. It offers an empirical study of the historical periods, countries, and families of political parties. The integration of major political and social cleavages (class division and Church-State, rural-urban, ethno-linguistic and religious divisions) makes it possible to assess the homogenizing impact of the left-right dimension borne of national and industrial revolutions, along with resistance to national integration by pre-industrial and center-peripheral cultural factors.