The only way for a united Germany with Austria (without deviating too far from the actual history) would be one of Austria or Prussia disintegrating during the 1866 war. For example if the Prussians had invaded Vienna (would have been possible, but risky) and broken up Austria, the German part of Austria could have been integrated into the new German state about to emerge.
Yeah, what he said.
The problem with Austrian unification of Germany is that the Habsburgs never really wanted a unified Germany, even with themselves at its head, after about 1648 or so, something what was virtually set in stone after the Great Turkish War. Austria was essentially attempting to maintain the status quo in the Confederation during the 1866 war, a status quo that involved Austria being the head of a divided group of Germans because they were a divided group of Germans. Co-opting the banner of Nationality would be virtually disastrous for the Transleithanian territories in the Habsburg empire, or for at least the Habsburg control over same...
Hmmm, thats an interesting idea... I wonder what would have happened to the rest of the Empire had that happened
Mostly what uppi said. Hungary either gets a Catholic Habsburg king, within the territories of the Kingdom of Hungary or maybe plus some Galicia. This is assuming that the Habsburgs don't get chased out entirely and replaced with the powerful Magyar magnates, to form a sort of oligarchic republic a la the plan of the revolt of '66. (Depends on what Russia does; considering the outcome of the Alvensleben Convention and the proposal made by Russia there, it's hard to resist the speculation that they'd get in on the landgrab, too.) Austria and Bohemia to Prussia-Germany, no question about it. Trentino is more difficult, considering Prussia's ally Italy went to war to help them gain it. As is Istria. I don't see anything good coming of that territorial question, and it would be interesting to see if von Bismarck gives the finger to the German nationalists' Grossdeutschland plan or to the Italian nationalists' irredenta...
Hungary would probably continue being ruled by the Habsburgs, trying to control the rest of the Empire, but ultimately failing in the non-Hungarian parts. Czech territory would probably have ended up in German hands, Slovakia would be divided between Russia and Hungary.
Since the borders of the Kingdom of Hungary are so convenient, I don't see them slicing it up much. Galicia is an awful big territory for Russia to eat. Geographically, too, it doesn't make a whole lot of sense for Russia to make a play for parts of Slovakia.
uppi said:
The interesting question is what would have happened to the Balkans. [...] So either the balkanisation of the Balkan would have happened earlier, or the Russians would have moved in. In such a scenario the German-Russian relations would be interesting. With the Balkan Question resolved in Russians favor, there might be not many reasons anymore for them to be at each other's throats. WWI would have played out very differently.
If the Habsburgs take over Hungary, I could see them making a play for the Balkans, to balance out the theoretically disproportionate power of their Hungarian subjects in such a state. A Hungarian Republic would be less willing to make such a play due to the probable exacerbation of ethnic tensions upon incorporating large numbers of Slavic subjects. But at the same time, Hungary can't just sit idly by and do nothing while the Russians break up the Ottoman Empire into a chain of Slavic sockpuppet states. They will probably partner with the British and French to prop up the Ottoman Empire. This may forestall the Russo-Turkish War of (OTL) 1877-8 - in which case Alexander will have a very interesting relationship with his Slavophile buddies - or it may widen the confrontation as Russia seeks to pull in new allies.
uppi said:
Of course this is all wild speculation...
I actually wrote a TL off of a somewhat similar scenario, which didn't involve the Prussians pressing the attack on Austria in 1866 but rather the French needing to make an international power play in Europe (the ACW was resolved early, so Napoleon left Mexico) in the aftermath of the Seven Weeks' War, which exacerbated tensions and forced a grand European conflict in the 1870s. There are some parts in which one can label the scenario
wild speculation, and obviously there must be limits on what we guess at, but some extrapolation is safe and possible.