In the reign of Peter the Cruel, its castle--considered with that of Segovia to be the strongest in Castile--was used for some time as the prison palace for that most unhappy princess, Doña Blanca, who, married to his Catholic Majesty, had been deposed on the third day of the wedding by the heartless and passionate lover of the Padilla. She was at first shut up in Toledo, but the king did not consider the Alcázar strong enough. So she was sent off to Sigüenza, where it is popularly believed, though documents deny it, that she died, or was put to death. The city belonged to the bishop; it was his feudal property, and passed down to his successors in the see. Of the doings of these prelate-warriors, the first, Don Bernardo, was doubtless the most striking personality, lord of a thousand armed vassals and of three hundred horse, who fought with the emperor in almost all the great battles in Andalusia. It is even believed he died wielding the naked sword, and that his remains were brought back to the town of which he had been the first and undisputed lord. The strong castle which crowns the city did not possess, as was generally the case, an _alcalde_, or governor; it was the episcopal palace or residence, a circumstance which proves beyond a doubt the double significance of the bishop: a spiritual leader and military personage, more influential and wealthy than any prelate in Spain, excepting the Archbishops of Toledo and Santiago. During the French invasion in the beginning of the nineteenth century, Sigüenza had already lost its political significance. The invaders occupied the castle, and, as was their custom, threw documents and archives into the fire, to make room for themselves, and to spend the winter comfortably. Consequently, the notices we have of the cathedral church are but scarce. The fourth bishop was Jocelyn, an Englishman who had come over with Eleanor, Henry II.'s daughter, and married to the King of Castile. He (the bishop) was not a whit less warlike than his predecessors had been; he helped the king to win the town of Cuenca, and when he died on the battle-field, only his right arm was carried back to the see, to the chapel of St. Thomas of Canterbury, which the dead prelate had founded in the new cathedral, and it was buried beneath a stone which bears the following inscription: "_Hic est inclusa Jocelini præsulis ulna._" From the above we can conclude that the cathedral must have been begun previous to the Englishman's coming to Spain, that is, in the beginning of the twelfth century. Doubtless the vaulting was not closed until at least one hundred years later; nevertheless, it is one of the unique and at the same time one of the handsomest Spanish monuments of the Transition period.