This book is a new approach to understanding monetary unions. This collaboration of scientists from different countries with leading professor and supervisor Slawomir I. Bukowski have prepared essays, which concern current and previous problems of functioning of monetary unions, especially the euro area. The contents of this book and the problems the authors have undertaken are very important and current in the situation concerning the world after the last recession and financial/fiscal crisis.This book embraces the problems of theoretical and historical fundamentals of monetary union with special concentration on the euro area, and discusses concerns of nominal and real convergence within the Economic and Monetary Union in the Europe, as well as problems of fiscal and monetary policy in the euro area. Problems of sociual policy and the issue of the financial markets role in the financing process of European companies.The conclusions that were made concern different problems of functioning of monetary unions, especially in the euro area, which will be very useful not only in debates between scientists, but also for politicians in the European Unions. The content of the book and the problems which are tackled in it are not a contribution to the discussion which is going on and which, in my opinion, will last for a long time because there are many things which are still not understood, and economic life in the globalized world poses many challenges which economists are trying to respond to.This book will be very useful and interesting for scientists economists, journalists, students and politicians.