The legal order created by the European Union (EU) has already become an established component of our political life and society. Each year, on the basis of the Union Treaties, thousands of decisions are taken that crucially affect the EU Member States and the lives of their citizens. Individuals have long since ceased to be merely citizens of their country, town or district; they are also Union citizens. For this reason alone, it is of crucial importance that they should be informed about the legal order that affects their daily lives. Yet the complexities of the Union’s structure and its legal order are not easy to grasp. This is partly due to the wording of the Treaties themselves, which is often somewhat obscure, with implications which are not easy to appreciate. An additional factor is the unfamiliarity of many concepts with which the Treaties seek to master the situation. The following pages are an attempt to clarify the structure of the Union and the supporting pillars of the European legal order, and thus help to lessen any lack of understanding among the citizens of the EU.