Queen of Navarre and Countess of Nemours. Daughter of Carlos III the Noble and Leonor de Trastámara, Kings of Navarre. In 1402 he/she married Martín the younger, King of Sicily. On the death of her husband, he/she returned to Navarre and in 1419, married the future Juan II of Aragon. On the death of Carlos III in 1425, Blanca was proclaimed Queen of Navarre, and her husband took the same title; from 1438 to 1440 took charge of the Government and negotiated the marriage of his son Carlos of Viana with Ines. Died, left the Kingdom and the County of Nemours in the hands of his son Carlos, although a testamentary clause which was depending upon the appointment of the approval of her husband Juan II, which provoked the civil war between the supporters of this (agromonteses) and those of the Prince of Viana (beaumonteses) established.