They will inherit the netherlands, maybe a younger son will get that.Assuming John has kids with Margaret, they will eventually inherit Austria and Burgundy after the death of Philip and Margaret. So there will still be a personal union between the Habsburg possessions and Castile-Aragon, but this time under a Trastamara. As for the imperial succession, John and Margaret's son could get the title of HRE, but it wouldn't be guaranteed, and the Electors could elect someone more German (like the Duke of Bavaria, a nephew of the late Emperor).
Well most likely cut the reign of Charles V and put directly Philip II... unless Burgundy is luckier and is directly given to the second son of Juan and Margaret.Would Trastámara Burgundy be any different from Spanish Habsburg Burgundy?
No, it would fully different.Well most likely cut the reign of Charles V and put directly Philip II... unless Burgundy is luckier and is directly given to the second son of Juan and Margaret.
Frederick the Wise of Saxony is most likely if Habsburg is not available, he was seen as possible compromise candidate IOTL.* Who becomes the new HRE emperor? The King of France? The Elector of Saxony?... The King of England?
No, it would fully different.
Take away Charles V with his idea of the Catholic Empire and the Burgundian heritage and you take away also Philip II.
You get instead a series of Spanish Kings more centered in the Iberian peninsula and the Mediterranean. The Burgundian lands would be perceived as something that it is not patrimonial and could be traded. Something like France cedes her claims on Naples and Milan, but Spain leaves Burgundy to a Trastamara prince married to a French princess.
However it is a really interesting scenario:
* Who becomes the new HRE emperor? The King of France? The Elector of Saxony?... The King of England?
* Do we have a Spanish invassion of North Africa? Maybe trying to secure the Western Mediterranean to make it an Spanish Lake?
* What about the relationship with Portugal and the lands recently discovered?