Diniz does not appear to have reformed in morals till late in life, when we are told that the saint won him to repentance by her prayers and unfailing sweetness. They had two children, a daughterConstantia and a son Affonso. The latter so greatly resented the favours shown to the king'sillegitimate sons that he rebelled, and in 1323 war was declared between him and his father. St. Elizabeth, however, rode in person between the opposing armies, and so reconciled her husband and son. Diniz died in 1325, his son succeeding him as Affonso IV. St. Elizabeth then retired to a conventof Poor Clares which she had founded at Coimbra, where she took the Franciscan Tertiary habit, wishing to devote the rest of her life to the poor and sick in obscurity. But she was called forth to actonce more as peacemaker. In 1336 Affonso IV marched his troops against the King of Castile, to whom he had married his daughter Maria, and who had neglected and ill-treated her. In spite of age and weakness, the holy queen dowager insisted on hurrying to Estremoz, where the two king's armies were drawn up. She again stopped the fighting and caused terms of peace to be arranged. But the exertion brought on her final illness; and as soon as her mission was fulfilled she died of a fever, full of heavenlyjoy, and exhorting her son to the love of holiness and peace. St. Elizabeth was buried at Coimbra, andmiracles followed her death. She was canonized by Urban VIII in 1625, and her feast is kept on 8 July.
(Taken from the Catholic Encyclopedia)