In the post-war period, the focus of governments in advanced democracies generally shifted from generalising basic education to staffing an increasing share of the population with more complex and specialised knowledge and skills through the expansion of secondary schooling. The demands of industrial development, heightened by the rise of the knowledge economy, meant policymakers across place and partisan divides have largely supported secondary expansion. However, despite these common trends lie ongoing differences across place in terms of the logic of the massification of secondary education; its ideal degree of differentiation among pupils and teachers, standardisation of teaching and pedagogical practices and the structure of control. This chapter analyses the patterns resulting from the policy choices of political parties and organized interests across advanced democracies in these three domains as well as the political determinants underlying these choices.