The native line of kings came to an end in 1234; their heirs intermarried with French dynasties. However, the Navarrese kept most of their strong laws and institutions. The death of Queen Blanche I (1441) inaugurated a civil war period between the Beaumont and Agramont confederacies with the intervention of the Castilian-Aragonese House of Trastámara in Navarre's internal affairs. In 1512, Navarre was invaded by Ferdinand the Catholic's troops, with Queen Catherine and King John III withdrawing to the north of the Pyrenees, and establishing a Kingdom of Navarre-Béarn, led by Queen Joan III as of 1555.