This chapter considers the structure of territorial cleavage from a national perspective. It focuses on patterns of polarization between regional electoral blocs, or “territorial oppositions,” in national politics. Axes of territorial cleavage arising between predominantly rural regions tend to take canonical forms associated with core–periphery politics in countries that are undergoing national economic integration and the growth of the central state. Stable axes of sectional competition, whereby leading regions square off against each other or against those on the periphery, are visible in the electoral data and in persistent policy cleavages in countries in this study. In broad outlines, these conform to models of territorial opposition in national politics advanced by earlier scholars (Lipset & Rokkan 1967; Gourevitch 1979; Bayart 2013). The analysis is built around four countries – Kenya, Zambia, Malawi, and Uganda – that serve as archetypes of different patterns of territorial opposition and core–periphery politics. Tanzania is a shadow case.