On 5 October 1530, Ferdinand was made Duke of Guarda by his brother, John III.[1] He married Guiomar Coutinho, 5th Countess of Marialva and 3rd Countess of Loulé, a rich heiress from a Portuguese noble family.[1][2] The marriage was arranged by John III. The couple settled in Abrantes, where their two children were born: a daughter, Luisa (born in 1531), and a son, born on 1 August 1533, who died shortly after his birth.
Luisa, his only surviving child, died in October 1534. Ferdinand himself died one month later, on 7 November 1534, in Abrantes.[1] He is buried in the Church of Saint Dominique of Abrantes. His widow, Guiomar Coutinho, died one month later, on 9 December.
* also an infante of Castile and León, Aragon, Sicily and Naples,§ also an infante of Spain and an archduke of Austria,# also an infante of Spain,‡ also an imperial prince of Brazil,¶ also a prince of Saxe-Coburg and Gotha, Duke in Saxony,◙ also a prince of Braganza,¤ title removed in 1920 as their parents' marriage was deemed undynastic,ƒ claimant infante