Among its saints may also be mentioned the martyrs of Cardeña, religious of the convent of the same name, who in the tenth century were executed by the Arab soldiers of the Emir of Córdoba in one of their numerous invasions of Castile; and St. Casilda, daughter of a Moorish king of Toledo, converted near Burgos whither she had gone with her father's consent to drink the water of some medicinal springs. She built a hermitage and died a saintly death.