Daughter of Garcias, King of Navare, and wife of Fernan Gonsalez of Castile. She twice saved the life of the count her husband, once on his road to Navarre, being waylaid by personal enemies and cast into a dungeon, she liberated him by bribing the gaoler. The next time was when Fernan was waylaid and held prisoner at Leon. On this occasion she effected his escape by changing clothes with him.
The tale resembles that of the Countess of Nithsdale, who effected the escape of her husband from the Tower on February 23rd, 1715; and that of the Countess de Lavalette, who, in 1815, liberated the count her husband from prison by changing clothes with him.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894