The queen of Castile, Joanna of Castile, married this member of the house of Habsburg who was the son of which monarch?
Philip I of Castile Philip I (22 July 1478 – 25 September 1506) called the Handsome or the Fair, was the first member of the house of Habsburg to be King of Castile. The son of Holy Roman Emperor Maximilian I, at the age of three Philip inherited the greater part of the Duchy of Burgundy and the Burgundian Netherlands (as Philip IV) from his mother, Mary, and at 27 briefly succeeded to the Crown of Castile as the husband of Queen Joanna, who was also heir presumptive to the Crown of Aragon. He was the first Habsburg monarch in Spain. He never inherited his father's territories or became Holy Roman Emperor because he predeceased his father, but his son Emperor Charles V eventually united the Habsburg, Burgundian, Castilian, and Aragonese inheritances.
Archduke Karl Ferdinand of Austria Archduke Karl Ferdinand of Austria (Vienna, 29 July 1818 – Gross Seelowitz (Židlochovice Castle), 20 November 1874) was the second son of Archduke Charles, Duke of Teschen (1771–1847) and Princess Henrietta of Nassau-Weilburg, and the maternal grandfather of King Alfonso XIII of Spain.