Manuel I of Portugal
Manuel's mother was the granddaughter of King John I of Portugal, whereas his father was the second surviving son of King Edward of Portugal and the younger brother of King Afonso V of Portugal. In 1495, Manuel succeeded his first cousin, King John II of Portugal, who was also his brother-in-law, as husband to Manuel's sister, Eleanor of Viseu.
Philip, Prince of Portugal
In 1537, he succeeded his brother Prince Manuel as Prince of Portugal, after his premature death. However, after his own premature death, two years later, after reaching six years old, his younger brother Infante João Manuel became the next Prince of Portugal.