Charles VI has a male heir

[Andrei]

In OTL , the Holy Roman Emperor Charles VI didn't have a male heir. Although his daughter , Maria Theresa , was recognised as the rightful leader in the Austrian Empire , his death meant the beginning of the war of the Austrian succesion .
In 1737 , Austria joined the Ruso-Turkish war on Russia's side. After some indecisive engagements , the Austrians were forced to sign the peace treaty of Belgrade ( the Ottomans recaptured Serbia and Lesser Wallachia from Austria ) in 1739 , because the emperor was about to die , and they needed the army to fight against Prussia , Bavaria and France , who didn't recognize Maria Theresa at that time.

So what would have happened if Charles had had a male heir ( supposing his son Leopold doesn't die or Maria Theresa is a boy , with another name of course )?
I suppose this would have eliminated the possibility of an Austrian Succesion War , so the Austrians could have won the war against the Ottomans.

Then what next?
The Austrians expand even more in the Balkans ( Moldavia , Wallachia and the mouths of the Danube were next on the list ) , about 40 years before the partitons of Poland ( the Russians were pretty far from the Dneister back then ). How far could they have expanded?
Could they have decided to support Poland , as a buffer and ally against Orthodox Russia ( the Russians won't be pleased to see the Austrians at the mouths of the Danube ) and Protestant Prussia ( Frederik would still want Silezia )?
How would the empire reform ? With such a large Orthodox population , and with more Slavs and Romanians than Hungarians it might have been more likely to become a federation of several peoples , rather than just Austria-Hungary.

[Wozza]

Oddly enough I was thinking of this the other day.
But I was looking at it the other way around - no Pragmatic Sanction.

Do not focus too much on the Balkans, great power rivalry will stop the Ottomans going down too fast.

The really interesting feature is Silesia - Prussia will not be a great power without it. And as you suggest perhaps no partition of Poland - with massive consequences.

The Anglo-French alliance might continue longer

[Dr Pervez Hoodbhoy]

The Anglo-French alliance might continue longer

It wasn't so much an alliance as a detente, and it was going to end as soon as the French invaded the Austrian Netherlands for whatever reason or some shots were fired in India or America. (That trigger is less likely though, since colonial militias/Native American tribes/Hindu states/Indies companies act as proxies.) It's going to be Russia's alliances that will be most affected by the POD - Prussia won't have to worry about any invasion from the east in TTL.

[Andrei]

Oddly enough I was thinking of this the other day.
But I was looking at it the other way around - no Pragmatic Sanction.

Do not focus too much on the Balkans, great power rivalry will stop the Ottomans going down too fast.

The really interesting feature is Silesia - Prussia will not be a great power without it. And as you suggest perhaps no partition of Poland - with massive consequences.

The Anglo-French alliance might continue longer

The Ottomans won't collapse faster , however Austro-Russian rivalry in the Balkans triggered WWI . In TTL , the Russians won't be present in the Balkans.

It depends on when Frederik attacks. If the war hadn't started in 1740 , the Austrians might have had time to enlarge and reform their army ( in OTL those reforms happened after the loss of Silesia and probably as a consequence of that loss ).

You mean a new Anglo-French alliance? Because Britain and France were enemies in the war of Spanish Succesion .