Irish membership of the European Communities in 1973 represented the most signicant development in the life of the independent state, and it helped to refashion the economic, political, and social landscape. Membership of the EU brought considerable change to domestic politics, and also to the executive and administration. Adjusting to a dynamic rules-based supranational order required adaptability and pragmatism. This chapter evaluates the impact of ‘Europe’ on Ireland, and the extent to which there are patterns of ‘Europeanization’ in politics and public life as a result of almost ve decades of EU membership. It argues that, domestically, Ireland used EU membership as a vehicle for modernization, while externally, the EU provided an increasingly important ‘geopolitical anchor’. And although this Europeanization has been far from uniform, the eect has been a move towards a more self-conscious ‘choice for Europe’. Brexit has conrmed this renewed commitment to European integration.