What POD could have resulted in a different outcome in the War of the Portuguese Succession, completely averting the Iberian Union; and what would be the effects of Portugal never being unified under Spain? There would obviously be no Portuguese Restoration War.
Separate Question:
What if Catherine, Duchess of Braganza or John I of Braganza were the victors of this succession crisis? What would be the effects of an earlier ascension of the Braganzas?