This chapter examines the revival of European integration from the mid-1970s to the late 1980s. It first considers leadership changes in the European Commission before turning to the European Council and the European Monetary System (EMS), the Commission’s southern enlargements, and the British budget rebate. It then discusses leadership changes in the Commission from 1981 to 1982, the Single European Act (SEA), and the European Council meeting at Fontainebleau in June 1984. It also looks at the initiatives of various Commission presidents such as Roy Jenkins, Gaston Thorn, and Jacques Delors. Finally, it describes the implementation of the SEA, widely seen as the big breakthrough in the revival of European integration.