[5] Catherine was Henry's preferred successor, but because of her sex, the powerful influence of Philip II, and the unpopularity of her husband, she failed to garner popular support.

[8] The heir by primogeniture was Catherine’s nephew Ranuccio Farnese,[a] being the son of her late older sister Maria,[10] followed by his siblings; then the Duchess herself and her children; and only after them, King Philip.

[15] In this regard, her prospects should have been bolstered by having a husband with direct royal lineage with whom she could share sovereignty and a son, Teodósio, that would serve as heir and successor to the throne.

[19] António promptly sought to claim the throne through popular acclamation in Lisbon, while Catherine and her husband adopted a more cautious stance, awaiting the findings of Henry's panel of jurists.

[23] These laws, purportedly enacted by the Cortes of Lamego in 1143 but now widely accepted to be fictitious,[24] asserted that no woman that married a foreign prince could inherit the Portuguese crown or transfer succession rights.