"The Kalmar Union (Danish, Norwegian, and Swedish: Kalmarunionen) is a historiographical term meaning a series of personal unions (1397–1523) that united the three kingdoms of Denmark, Norway (with Iceland, Greenland, Faroe Islands, Shetland, and Orkney), and Sweden (including a part of modern day Finland) under a single monarch, though intermittently and with a population less than 3,000,000.
The countries had not technically given up their sovereignty, nor their independence, but in practical terms, they were not autonomous, the common monarch holding the sovereignty and, particularly, leading foreign policy; diverging interests (especially the Swedish nobility's dissatisfaction over the dominant role played by Denmark and Holstein) gave rise to a conflict that would hamper the union in several intervals from the 1430s until the union's breakup in 1523 when Gustav Vasa became king of Sweden."
The establishment of a single currency zone with a unified monetary policy that rules all countries in Europe have shown mixed results. The north, the south, the center and the east have all shown signs of divergence instead of the desired convergence.
So would it be better, instead of having a monolithical system, splitting the control into smaller more manageable entities - The north by re-establishing the Kalmar system , for the South by creating the "Calamares" (...let's not call that PIIGS...) entity , the center by creating the Franco-German Group ...."