The Maastricht Treaty was signed in 1992 which know as the symbol of the establishment of European Union.

The Maastricht Treaty marked the cooperation of European countires became more close and expanded from economic regions to politic, military and diplomatic regions. The predecessor of European Union is European Communities which only made cooperation among economic as European Coal and Steel Community and  European Atomic Energy Community. Now with the new signed treaty Eurpean countries strated more comprehensive cooperation such as common currency and the expansion of Parliament’s power.