Alfonso X of Castile vs Joanna of Castile

Alfonso X commissioned the Alfonsine Tables, a set of astronomical tables based on Ptolemaic models. These tables were used by European astronomers for centuries and became a standard reference in medieval science.

Alfonso X of Castile was elected King of Germany by a faction of prince-electors, opposing Richard of Cornwall. This election was part of the Great Interregnum, with Alfonso receiving support from the Hohenstaufen loyalists and the Papacy.

Alfonso X never traveled to Germany to assert his claim to the throne. His absence weakened his authority, and he was unable to secure effective control over the German kingdom, leaving the title contested.

Alfonso X formally renounced his claim to the German throne in favor of Rudolf of Habsburg. This renunciation ended the Great Interregnum and allowed Rudolf to be recognized as the legitimate king of Germany.

After the death of her husband Philip I, Joanna of Castile became the nominal queen of Castile. However, her father Ferdinand II of Aragon and later her son Charles I of Spain assumed regency, citing her mental instability. Joanna was confined to the castle of Tordesillas for the rest of her life.

After the death of her husband Philip I, Joanna refused to remarry, despite pressure from her father Ferdinand II and other nobles. Her refusal was interpreted as a sign of mental instability, but it also reflected her deep attachment to Philip and her desire to maintain her independence.

Joanna of Castile was confined to the Royal Palace of Tordesillas by order of her father Ferdinand II, who declared her unfit to rule. She remained imprisoned there for 46 years, isolated from political affairs, while her son Charles I governed Castile in her name.