Key historical events leading to the establishment of the European Union include the aftermath of World War II, which highlighted the need for economic cooperation to prevent conflict. The Treaty of Rome in 1957 created the European Economic Community (EEC), promoting economic integration. The fall of the Berlin Wall and subsequent enlargement in the 1990s further strengthened ties among European nations. The Maastricht Treaty in 1992 formally established the EU and introduced a framework for political and economic unity, paving the way for a single market and, eventually, the Euro currency.