Anyhoo, this was originally meant to go with a piece about the "European Federation"; the equivalent of the European Union in the Dragons Unite timeline. That being said, that's not the best way to describe it...basically, in this timeline, the Empty Chair Crisis escalated and the European Economic Community ended up fracturing into a pro-union half in the west, and a pro-federation half in the east. The latter eventually unified into a single state, while the rest of Europe formed their own trade pacts instead of choosing sides between subfactions during the Cold War. Post-Cold War, though, the federalist half ends up resurrecting the idea of forming a European Community, and manages to convince several closely aligned states to join with them (ATM in-story they just annex them, but that's something we'll revise eventually...it was inspired by a lengthy bout of CKII gaming where 'swearing fealty' is a handy mechanic), and then over the centuries to come other they steadily win over a good number of the other states of Europe...
So, haven't got exact dates for it yet, but the various shades of green indicate at what time everybody joined. Ranging from darkest to lightest...
1 - The "Avalarian Empire"; the end result of the initial European Federalisation project.
2 - The "Core Four" initial member states; the Kingdoms of Hungary, the Isles and Mallorca, and the Principality of Quatremurs (previously in a sort of personal union with Avalar).
3 - The NORDEK remnants; the Kingdoms of Denmark and Man, the Tsardom of Karelia and the Republic of Iceland, all of whom joined during the Avalo-Sekeolasian War.
4 - The former territories of the "Union of Northern States" (Sekeolasian Empire), reconstituted following the conclusion of the Avalo-Sekeolasian War, and the Austrian Empire, which joined in the aftermath.
5 - The Baltic expansion; the German Empire, the Grand Duchy of Prusa, the Republics of Estonia, Latvia, Lithuania and Poland, and the Free City of Danzig, all of whom joined following negotiations to unite their two respective trade pacts.
6 - The Central European expansion; the Kingdoms of Navarre and Rome, the Republics of Lombardy-Venetia and Tuscany, and the State of Romania, all of whom joined following negotiations to unite their two respective trade pacts.
7 - The Western European Union expansion; the Kingdoms of Ireland, Spain and Portugal, the Principality of Andorra and the French Republic, all of whom joined following negotiations to unite their two respective trade pacts.
8 - The United Kingdom, which <insert topical joke here laughing at what a shitshow it all is>.
Oh, and there's a different flag for the European Federation, which is why the colour scheme is green! Don't seem to have a picture of it handy at the moment; it was inspired by this picture (commons.wikimedia.org/wiki/Fil… ) back when it was still on the Wikipedia page, but it seems to be a unique design so we'll probably tweak it slightly. Anyhoo, post any questions in the comments and I'll elaborate further...
Labelled version of the map here;
Dragons Unite copyright Ddraigtanto
From memory, the Empty Chair Crisis was basically France under Charles de Gaulle being difficult and constantly vetoing attempts by the rest of the European Community to implement supranational laws and systems, while proposing their own systems where France was either in charge or everything was super decentralised which the other states in turn rejected (France also kept blocking applications for new members because they thought it'd allow the United States and NATO to exert control over them). In the end things reached a breaking point and the French diplomats walked out, but the other states managed to work out a compromise of sorts (really them just 'agreeing to disagree') and a few years later Charles de Gaulle was toppled from power, at which point France stopped being difficult and allowed other members to join.
In this timeline, the European Community fractured instead; the setup of the member states was different (Germany and Italy had been carved up into smaller states after WWII, the fictional Kingdom of Avalar was looking to exert influence in the area, and the Scandinavian countries had formed their own pact already) and a rivalry between Pro-Union and Pro-Federation members had developed by this point, so the Pro-Federation states decided to just kick France out and the rest of the Pro-Union members followed them.