Blanche II of Navarre

Blanche II (9 June 1424 – 2 December 1464) was a Navarrese princess and claimant to the throne of Navarre. She was the daughter of John II of Navarre and Blanche I of Navarre, and was recognized early in life as an heir in the line of succession. Her marriage to Henry IV of Castile, arranged to secure peace between Navarre and Castile, ended in annulment. After returning to Navarre, she supported her brother Charles, Prince of Viana in his dispute with their father over the crown. Following her brother's death, she became a rival claimant but was detained and later transferred to France, where she died under uncertain circumstances.

Source: Wikipedia — https://en.wikipedia.org/wiki/Blanche_II_of_Navarre