Alfonso III. of Leon, and Alfonso IX. King of Castile, were cousins, but there were dissensions between them. The King of Leon, to strengthen himself, married his cousin, the Princess Theresa, daughter of his uncle, the King of Portugal. By her he had two daughters. The marriage was annulled by Pope Celestine III. on account of their consanguinity, and, on their making resistance, they were excommunicated and the kingdom laid under an interdict. This produced an unwilling separation in 1195. Alfonso III. did not long remain single. Fresh dissensions having broken out between him and his cousin Alfonso IX. of Castile, they were amicably adjusted by his marrying the Princess Berenguela, daughter of that monarch. This second marriage, which took place about three years after the divorce, came likewise under the ban of the Church, and for the same reason, the near propinquity of the parties. Again the commands of the Pope were resisted, and again the refractory parties were excommunicated and the kingdom laid under an interdict. The unfortunate king of Leon was the more unwilling to give up the present marriage, as the Queen Berenguela had made him the happy father of several children, one of whom he hoped might one day inherit the two crowns of Leon and Castile. The intercession and entreaties of the bishops of Castile so far mollified the rigor of the Pope, that a compromise was made; the legitimacy of the children by the present marriage was not to be affected by the divorce of the parents, and Fernando, the eldest, the subject of the present chronicle, was recognized as successor to his father to the throne of Leon. The divorced Queen Berenguela left Fernando in Leon, and returned in 1204 to Castile, to the court of her father, Alfonso III. Here she remained until the death of her father in 1214, who was succeeded by his son, Enrique, or Henry I. The latter being only in his eleventh year, his sister, the ex-Queen Berenguela, was declared regent. She well merited the trust, for she was a woman of great prudence and wisdom, and a resolute and magnanimous spirit.