Peter von Portugal
This alternative hypothesis seems more logical than the original hypothesis that insists on identifying the man-in-the-chaperon as Prince Henry. Since Henry was a bachelor, it is not obvious what woman would be suitable to pair with him as the standing figure on the left. His closest female relatives were his mother Philippa and sister, Isabella, Duchess of Burgundy, both of whom would be more properly paired with their husbands. Moreover, Isabella did not live in Portugal after 1430, thus her lack of involvement with Portuguese society at the time the panel was painted would probably disqualify her from inclusion. If the uncle of a king were to be incorporated in the panel, it would more properly be Peter, Duke of Coimbra, who was once the regent of Afonso V and the father of his bride.