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All the Habsburgs of OTL descend from Ernst I ‘der Eiserne’, Archduke of Austria and his second marriage to Cymburgis of Masovia (who passed the genes for what later became the Habsburg lip and prognathism into the family). However, Ernst had two older brothers (discounting the Albertine line) ahead of him in the succession who died without issue.

His eldest brother, Wilhelm, was married to the twenty-seven-year-old Giovanna II, Queen of Naples. They were married for five years with no children, and before marrying Giovanna he'd been a betrothed to Jadwiga of Anjou, Queen of Poland. His second brother, Leopold IV, married Catherine of Burgundy, but the marriage of nearly twenty-years left no issue. So naturally, Ernst succeeded to the Leopoldine line’s entire possessions.

So what if Wilhelm and/or Leopold IV had left kids (read: sons) to succeed to their titles – and in Wilhelm’s case, to their mother’s? How would this affect the Habsburgs development? Especially if the Ernestine line of the Leopoldines (at least the generation of Friedrich V (Holy Roman Emperor Friedrich III)) is still in existence. Would it mean that the Habsburgs could still climb onto the Imperial throne (assuming the Luxemburgs or the Albertine line are likewise unavailable as OTL)? Or at least be able to make themselves a pre-eminent family in Germany? Or would they be considered too foreign if they also rule the kingdom of Naples/Poland?
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