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.
Ladislaus IV of Hungary Ladislaus the Cuman (Hungarian: "IV. (Kun) László" , Croatian: "Ladislav IV. Kumanac" , Slovak: "Ladislav IV. Kumánsky" ; 5 August 1262 – 10 July 1290), also known as Ladislas the Cuman, was king of Hungary and Croatia from 1272 to 1290. His mother, Elizabeth, was the daughter of a chieftain from the pagan Cumans who had settled in Hungary. At the age of seven, he married Elisabeth (or Isabella), a daughter of King Charles I of Sicily. Ladislaus was only 10 when a rebellious lord, Joachim Gutkeled, kidnapped and imprisoned him.