In 1380-1381, King Ferdinand I of Portugal secretly allied with King Richard II of England and John of Gaunt, and agreed to a betrothal between his daughter and heir, Beatrice, and Edward of Norwich, eldest son of Edmund, Duke of York. The eight-year-old Edward was even brought to Lisbon for the betrothal.
In the end, she married King John I of Castille, but was driven out and never recognised as Queen by the Portuguese nobles, who instead named John, Grand Master of the Order of Aviz and an illegitimate half-brother of Ferdinand, as King. Edward of Norwich, meanwhile, married Philippa de Mohun (who was 20 years older than him and had, between two husbands, had given birth to just one son) before he was killed at the Battle of Agincourt saving the life of King Henry V.
What if the planned marriage between Beatrice and Edward had gone through? There would be no fear by the Portuguese nobles of a Castillian union, so not as much opposition to it as the marriage betwen Beatrice and John I of Castille. Would Edward still have been allowed to become Duke of York upon his father's death, or would the title have passed to his younger brother, Richard, instead?
Any thoughts?