
The European Union is unique among the nations of history. Most governing bodies are built around a culture and language that is shared amongst the people they rule, which is then followed by a shared system of laws, courts, defense forces, currency etc. Or, in the case of an empire, the system hinges upon military dominance, which then enforces those conditions on every culture it can gobble up.
But the European Union is the only nation (to my knowledge) that attempted to use monetary and economic policy (the Euro) to unite a diverse set of culture, before turning into a real government in its own right. The only thing missing from the EU, is its own standing army. While each EU nation has a military, they still exercise some degree of sovereignty over their defense forces (at least on paper).