The Realms of the Danubian Alignment, the Lands Ruled by Her Imperial and Royal Apostolic Majesty Andrea the Second, Holy Roman Empress of the German Nation, of This Name the First, Empress of Austria, Apostolic Queen of Hungary, Queen of Bohemia, Croatia and Illyria; Queen of Jerusalem, Archduchess of Austria, Duchess of Salzburg, of Styria, of Carinthia and Slovenia, of Carniola and of Slevania, Margravine of Moravia; Princely Countess of Habsburg and Tyrol, Princess of Trent and Brixen; Lady of Trieste, in the Windic March and of the Pannonian Avars.
Ahem.
Austria
Imperial Archduchy of Austria
Once the beating heart and core of the Habsburg Monarchy, it has increasingly been pushed out of that role by the Hungarians, much to Austrian nationalists' alarm. Before Germany fell, there was a growing schism in the far-right between "Austrofascists" [aka those who fetishes the twelve year dictatorial rule of Engelbert Dolfuss in the 30s way too much] who argue that Austria needs to reassert control over the Alignment and "put the Magyars back in their place" while rejecting any talk of German unification as against Austrian [read: Catholic] values, and those of the "National Freedom Party of German-Austria" that argue that the German people of Austria [including Bohemians] should leave the Alignment and join Germany.
Her Imperial and Royal Apostolic Majesty is of course, non-political, but she is known to be a firm nationalist. Her move to declare herself the Holy Roman Empress with South German monarchies' support in the midst of the German civil war has somehow managed to unite most Austrians behind her. The more ""moderate"" German-nationalists split from the NFP [which of course support the NFP regime] and formed the "Imperial-Democratic League", a fiercely pan-German and pro-Habsburg movement. It is still third in the polls, but it has done well, comparatively.
Hungary
Kingdom of Hungary
Lands of the Crown of Saint Stephen
The current "top dog" in the Alignment, the recent declaration by the Empress has unnerved them somewhat. However, the Empress is nothing if not canny, and has arranged for a separate coronation as Queen of Hungary in the new year, her second coronation as Queen of Hungary but her first as solely that and not as the wider Empress. It is planned to be heavy in symbolism. The current Chief Minister of Hungary is a firm loyalist to the Crown, and wholeheartedly backs this move. The republicans mutter that it's just meaningless symbolism. Still, the people seem to like the idea.
Bergetalia
Crown Lands of Bohemia, Moravia and Slevania
"Bergetalia". Even the name alone tells you it's an artifical construction. Created as part of the awkward post-WWI compromises that radically changed the old Austrian Empire into the Danubian Alignment, it is an awkward union of three radically different nations.
- Kingdom of Bohemia
A nation heavily split by language, with the Sudeten Germans and the Czechs often clashing on which language should take priority - German or Czech, alongside Bohemian. Meanwhile the Bohemian speakers, the silent majority, just sit there and hope the two tire each other out.
- Margraviate of Moravia
Firmly Czech speaking, it feels squeezed between the Slevans, the Hungarians, the Bohemians and the Silesians. A Slavic nation surrounded by non-Slavs, it has acquired a very strong pride in itself and is known as the "Loud Dwarf" of the Alignment for often having politicians that muscle their way into getting Moravia what it wants, and damn the consequences.
- Duchy of Slevania
A land speaking a Romance language close to that of the neighbouring Venedic people, there has often been Slevan politicians arguing for an union of the two countries, similar to the German-nationalists. Indeed, once you could easily find Pan-Venedic, Pan-German, Pan-Italic and Pan-Slavic nationalists enjoying meals together in Vienna as political allies in a common cause
- that of breaking the Alignment. Otherwise, it is rather quiet.
Croatia
Kingdom of Croatia
The Croats have historically been the most sceptical of the Alignment and the Empress' recent actions have not engendered it to them, honestly. They once had a referendum in the late 1990s that was planned by a right-wing nationalist party and was held under a centre-left and firmly pro-loyalist government, with a landslide majority of 78% for staying. Many decried it as fake, but after two years of unrest, the place simmered down.
Carinthia-Slovenia
United Duchies of Carinthia and Slovenia
Once the United Duchies of Carinthia and Carniola, the later changed its name officially to "Duchy of Carniola and Slovenia" as a compromise in favour of Slovenian nationalists, and the United Duchies changed its name to match the more-used name five years later. Mostly German-speaking, but Slovenians have a firm majority in Carniola-Slovenia and the language seems to be reaffirming itself as a sign of local pride.
Tyrol
Princely County of Tyrol
Those days the government of Tyrol has sent quite a few "diplomats" south to Italian countries, a move that has concerned foreign-policy wonks in favour of the Alignment. However, it is very unlikely that Tyrol would break completely free from the Alignment, as polling suggests that it is one of the most firmly-monarchist parts of the Habsburg Monarchy.
Styria
Duchy of Styria
The only Muslim-majority state in the entire region, surrounded by Christians. The Muslim-majority was the result of a series of migrations north after brutal Muslim persecution in Serbia and in Byzantium. Unluckily, they ended up in the land most likely to persecute them centuries later. Still, they have persevered. And in the Agreement of 1920, Styria finally got independence. Sure, by this point they mostly speak German, but it's still momentous.