Since 2004, the European Union has admitted thirteen new member-states, eleven of which were post-communist countries that had gained independence from Soviet hegemony or Yugoslavia between 1989 and 1991. The EU’s post-communist enlargements were its most ambitious in terms of the territory incorporated, the number of citizens admitted, and most importantly, for the sweeping political and economic transformation required of candidate—now member—states. The Eastern enlargement has been qualitatively different from such earlier attempts at integration, democratization and wealth creation and this panel examines its consequences ten years on, assessing the new possibilities for prosperity in East Central Europe. First, the papers ask whether the EU has helped mitigate long-standing disparities between East and West. Second, they explore whether the EU, and its constituent members, act as a different, and for supporters of capitalism and democracy, a better ruling regime—such that accommodation and imitation by ECE states in the post-communist period lifts the fortunes of populations there. Third, the panel also examines whether EU reform efforts in the Western Balkans remain robust in spite of the enlargement fatigue among some of the older EU members, and the intensity of the eurozone’s economic crisis over the last four years. The panel thus assesses the continuing important differences between East and West and highlights the issue-areas in which the EU transcends but also reinforces the centuries-old partition between Eastern and Western Europe.