Would a Louis XIV-Maria Teresa match go through? Mean, OTL Felipe had sons in the 1650s so he was kinda "sure" (even if they died like flies) there'd be no French inheritance. Here, he'd likely have Maria Teresa sworn in as Princess de Los Asturias as soon as her brother dies, no?
Likely. Wonder who is her husband ITTL?
OTL Felipe had sons in the 1650s, though even then it was a bit touch and go. At the start of the decade, his original heir, Baltasar Charles was already four years in the grave, and by the end, his spare died young and his second heir (Felipe Prospero) was suffering from a severe case of epilepsy (he died in 1661).
I decided the PoD be the ATL pregnancy, so the gender of child can be switched (different spermatozoid wins the race).
If Leopold becomes King of the Romans. Assuming the PoD is Isabella not dying in 1646, butterflies could allow for Ferdinand IV, King of the Romans to also not bite the dust. (he dying from Smallpox in 1654, as his cousin, Baltasar Carlos, did eight years prior) So there is a possibility of avoiding a Karl V situation while still keeping Leopold as her betrothed.
His Tyrol cousins managed just fine in this situation (only the diff being 12 years).
IOTL she died in 1644 after miscarriage. ITTL the pregnancy is different (resulting in the Infanta but the physicians declare the Queen can't have anymore kids) and she lives to the age of her sister Henrietta Maria, dying at the age of 60 (still predeceasing her hubby dearest by 3 years).
By the way, who is his wife in this scenario (he can't afford the heiress presumptive-but-quite-likely apparent to Spanish throne - so by 1654 he's married elsewhere)?
While IOTL, the plan was for Maria Teresa was to marry Ferdinand IV, because the need to avoid a Karl V scenario that would disturb ally and enemy alike, could Ferdinand marry Eleonora Gonzaga (OTL, Ferdinand III's second wife) instead? The two are closer in age to each other vs. to Ferdinand III, and if Ferdinand III's second wife doesn't die giving birth to Karl Joseph, I can see it being a viable option.
Third. And there is a sister of Ferdinand III second wife, who is 4 years older than Ferdinand IV, and whose place in Mantua is likely taken by Mariana of Austria ITTL. She had a single kid (OTL last Duke of Mantua) in 1652, so she'll do if we go for minimal number of butterflied away deaths.
I heard of typhoid fever as a possible cause of death. But yes, ITTL his schedule is different, which may mean his survival.
Сomparatively. Felipe IV came from the family of 5 people living to adulthood and all these from related marriage - so managing 3 kids living to adulthood in unrelated one is not much a feat (though a feat of delaying inbreeding degradation 1-2 generations into the future).
