Best PoD for an Austrian Empire collapse in the 19th Century

Exactly as the title says, what's the best PoD between the Congress of Vienna (1815) and 1899 that results in a fragmentation of the Austrian Empire/Austria-Hungary?

I suppose the 1848 Hungarian Revolution was a close call, and it gave a serious blow to the Austrian monarchy, so much that it took foreign intervention from Russia with a curb-stomping army to end the party. By then, however, Russia and Austria had this sort of "reactionary pact" to prevent the spread of revolutionary ideas.

About later dates, I'm not so sure, as they would perhaps involve the ruin of A-H at the expanse of another European power - I suppose a more violent Prussian victory could put the Habsburg monarchy on the ground (but I don't think even Prussia desired a complete breakdown of Austria)... or a Sardinia-Piedmont victory in the unification of Italy (allied with France, of course), but then I find it very unlikely that the Great Powers would like to see the collapse of Austria in these contexts, especially if the neighboring Ottoman Empire is passing through a similar process of fragmentation.

Any ideas? I'm particularly more interested in a scenario that allows for the ressurgence of the ethnic groups from within the empire, mainly the Hungarians, the Romanians and Slavs.

1848 is the standard one. WI the 1848 revolutions were more successful could be a really cool scenario, if done carefully.

Aside from the revolutions of 1848-49, there's the inter-German hostility of the 1860s. Prussia had established relations with various Hungarian, Romanian and Slavic separatist movements and governments and was willing to partition Austria with them if it stays too hostile to Prussia. A PoD in the Austro-Prussian War, the Franco-Prussian War or something in between those could have plausibly led to the end of the Habsburg empire and a radical rearrangement of central Europe.

It has to be either the Revolutions of 1848 or an unsuccessful Augslich in 1867.

For the 1848 scenario, perhaps delay the November Uprising to coincide with the 1848 revolutions, or alternatively have another Uprsing. Either way, Poland is going to have to blow over for Russia to be distracted by something else entirely for that to be pulled off.

Even then, the most I could potentially imagine would be for an 1848 scenario, assuming it hasn't been completely botched is the splitting off of Hungary, Galicia-Lodomeria and Lombardy-Venetia, compared to just Hungary (with or without Croatia) for 1867.

How about Austria sides with Russia in the Crimean War, and Prussia and Sardinia jump on her with British and French help?

Noblesse Oblige said:

It has to be either the Revolutions of 1848 or an unsuccessful Augslich in 1867. (...)

Click to expand...

I went to check out the context of the Augsleich... and apparently it arose from the disastrous defeat suffered by Austria at the hands of Prussia and France in the 1860s. Indeed, it almost collapsed, as its political, military and economic situation was dire. Also, according to the Wiki:
"The Compromise was negotiated and legitimised by only a very small part of Hungarian society (suffrage was very limited: less than 8 percent of the population had voting rights), and was seen by a very large part of the population as a betrayal of the Hungarian cause and the heritage of the 1848-49 War of Independence. The Compromise was very unpopular and the government resorted to force to suppress civil dissent. The Compromise caused deep and lasting schisms in Hungarian society."

Now that I think about it, perhaps that might be an interesting PoD. Russia won't be able to help, as it did in 1848, if a wave of nationalist uprisings occur inside the empire, as it's still licking its wounds from the Crimean War.

France is a wild card, as it depends on Napoleon III's humor... but it possibly won't be interested in preventing the collapse of Austria, as long as it doesn't means the strenghtening of Prussia and Sardinia-Piedmont...

I'm not sure about the UK. Will they be interested in intervening to prevent Austrian collapse? Unless the Parliament adopts an isolationist stance, they would desire to maintain stability in Austria to check the balance of power against Prussia and Russia in central Europe.

EDIT: Now that we're on it, did the Czech and Slovak peoples had separatist feelings as much as the Hungarians and the south Slavs? I ask this because I think that even if Hungary, Galicia-Volhynia and Bosnia/Herzegovina break apart, the Austrian Empire might perfectly survive with Bohemia, Moravia, Slovakia, Slovenia and perhaps the north of Croatia.

I really don't like to bump... but any other ideas on this topic?