The history of the European Union began after World War 2 when Europe was divided between Western and Eastern blocks. In 1951, six countries formed the European Coal and Steel Community to promote trade and rebuild after the war. This led to the formation of the European Economic Community in 1957 to create a single market. The European Union continued expanding to include more member states over time and implemented policies like the Euro currency and allowing free movement between countries. Key treaties and agreements helped further European integration and cooperation.