As you all know, the Habsburgs sold their soul to the devil to roll nat 20s in the 15th and early 16th century which got them Burgundy, Spain and Bohemia&Hungary.
Now what if they only inherited Burgundy but not the others?
This can be achieved survive by having Joannas brother John or Miguel da Paz, her nephew, survive longer and make heirs of their own. A surviving house of Trastamara alone already has a huge impact on history. For one, Spain would most likely not bankrupt itself fighting the Dutch. What would Spain do with all that wealth if not fight the Dutch? What would their relations to France look like? Would they still fight each other over Italy?
To keep Bohemia and Hungary out of the claws of the Habsburgs Louis II would have to survive too. Since the Jagiellons would rule over a vast empire in central eastern Europe and Bohemia would still be part of the HRE, could a Holy Roman Emperor be a Jagiellon? Could a strong Poland-Lithuania-Bohemia-Hungary (PLBH) stand against Muscovite expansion? Could a strong PLBH even expand into Muscovy?
The Habsburgs without the resources of the Spanish empire and wealth of Bohemia-Hungary would be seriously deprived. However, it would also take a huge burden off of their shoulders as Poland-Lithuania-Bohemia-Hungary could be a buffer between them and the Ottomans. PLBH, Spain and Austria-Burgundy could coordinate an alliance against the Ottomans.
So the only threat the Austrians would have is France, Venice and the reformation.
Can the Habsburgs defend against the French without Spanish resources and the wealth of Bohemia-Hungary?
I believe the Habsburgs and the Jagiellons would be on good terms and France couldn't use them against the Habsburgs since otherwise PLBH would be surrounded by enemies. Both the Habsburgs and PLBH would have an interest of not making an enemy out of each other. The English would be another natural ally for Austria-Burgundy as both don't want the French to become too powerful.
Now what if they only inherited Burgundy but not the others?
This can be achieved survive by having Joannas brother John or Miguel da Paz, her nephew, survive longer and make heirs of their own. A surviving house of Trastamara alone already has a huge impact on history. For one, Spain would most likely not bankrupt itself fighting the Dutch. What would Spain do with all that wealth if not fight the Dutch? What would their relations to France look like? Would they still fight each other over Italy?
To keep Bohemia and Hungary out of the claws of the Habsburgs Louis II would have to survive too. Since the Jagiellons would rule over a vast empire in central eastern Europe and Bohemia would still be part of the HRE, could a Holy Roman Emperor be a Jagiellon? Could a strong Poland-Lithuania-Bohemia-Hungary (PLBH) stand against Muscovite expansion? Could a strong PLBH even expand into Muscovy?
The Habsburgs without the resources of the Spanish empire and wealth of Bohemia-Hungary would be seriously deprived. However, it would also take a huge burden off of their shoulders as Poland-Lithuania-Bohemia-Hungary could be a buffer between them and the Ottomans. PLBH, Spain and Austria-Burgundy could coordinate an alliance against the Ottomans.
So the only threat the Austrians would have is France, Venice and the reformation.
Can the Habsburgs defend against the French without Spanish resources and the wealth of Bohemia-Hungary?
I believe the Habsburgs and the Jagiellons would be on good terms and France couldn't use them against the Habsburgs since otherwise PLBH would be surrounded by enemies. Both the Habsburgs and PLBH would have an interest of not making an enemy out of each other. The English would be another natural ally for Austria-Burgundy as both don't want the French to become too powerful.