In this chapter we set out the objectives of the book and we introduce the common analytical framework to analyze territorial heterogeneity in the vote which is applied in each of the country chapters. We compare 10 eastern european countries to 13 west european countries which allows us to explore differences in congruence between regional and national elections and second-order effects in regional elections. The comparison also helps us to suggest indicators for tracing regional election effects specific for eastern european regions. In addition, we propose territorial cleavages, regional authority, and electoral rules as factors which may account for regional electoral dynamics in east european regions. The chapter ends with a discussion...