The Aragonese mostly remained faithful to Philip, but held firmly to their privileges; and when in the autumn of 1645 he summoned the Cortes of Saragossa and Valencia to swear allegiance to Baltasar Carlos, they drove a hard bargain, and Philip was forced to concede many legislative demands of the members, in return for sparing votes of supply. The tale he told to the Castilian Cortes summoned early in 1646 in Madrid was disconsolate in the extreme. All was spent: the wars still went on in Flanders, Germany, Italy, and Catalonia, as well as on the Portuguese frontier, and the regular revenue was utterly insufficient. The deputies were as much afflicted by the penury of their constituents as the King was by the emptiness of his treasury, but with many groans they voted an immediate grant of a million and a half of ducats in money, and in the following year an extension of the special war taxation upon food, and leave to sell pensions was granted.

Almost every week beseeching letters went from Philip to the nun, praying for her intercession with the Almighty to aid him in his troubles; and the replies of the good woman were always wise, as she inculcated hope and labour without remission. Sometimes Philip's faith weakened, and he almost despaired, for he was convinced that all the national trouble arose from his personal sins, and yet, as he says, he could not help sinning. In the meanwhile disasters fell upon his arms thick and fast, and the national distress became more intense. He could suffer his own troubles, wrote Philip, for he knew that he had deserved them; "but to see the sufferings of so many poor innocent people in these wars and conflicts pierces me to the very heart, and if with my life's blood I could remedy it I would expend it most willingly."

When Philip returned to Madrid for the winter of 1645-46, Sor Maria's constant exhortations had prevailed upon him to make a determined attempt to cleanse Madrid of some of its blatant vice in order to win God's favour. She was particularly strong in her condemnation of the dress and demeanour of the women of the capital, and a severe pragmatic on the subject was issued: the playhouses, to the dismay of the comedy-loving people, were rigorously closed,[[21]] the press-gangs that scoured the country for recruits were enjoined to be merciful to the poor in their operations, and other measures urged by the nun became the law of the land, whilst the lethal crimes so common in Madrid were prosecuted now with merciless severity.

Leaving his capital at least outwardly more decent, Philip travelled north again in April 1646, accompanied by his promising young son, now approaching manhood; Pamplona, the capital of Navarre, being taken on the way, in order that the Navarrese Cortes might swear allegiance to the heir. No sooner had they entered Pamplona, late in April, than Baltasar Carlos fell seriously ill of tertian fevers; and the nun's prayers were frantically supplicated for the boy by his afflicted father, who would not leave his son's side, although the Aragonese were getting clamorous for his coming to direct the campaign, which had already been opened by the enemy, who were actively besieging Lerida. After two months' delay, Philip at length entered Saragossa in June, when he received the news of the death of his sister, the Empress Maria, who had been betrothed to Charles, Prince of Wales. This, coming on the top of all his other troubles, almost broke the poor King down. "If I did not recognise that my troubles are sent by God, as warnings for me to prepare my own salvation, I could hardly tolerate them.... Help me, Sor Maria, to pray to Him; for my strength is small, and I fear my weakness."

Baltasar Carlos dies

A greater blow than all fell upon him soon afterwards. An insincere embassy had been sent to England some little while before, in order to frustrate the betrothal of Mary Stuart, daughter of Charles I., with the Prince of Orange; and the means employed had been the old suggestion of the marriage of an English Princess with Baltasar Carlos. It came to nothing, and, so far as the Spaniards were concerned, was a mere feint from the first, for the real wish of Philip's heart, as it had been that of his father, was still further to cement the two branches of the house of Austria, by marrying his heir to the Emperor's daughter. Imperial ambassadors were at Saragossa when Philip arrived, and the King wrote cheerfully to the nun soon after, saying that the marriage of Baltasar Carlos had now been settled, and that his niece Mariana of Austria was betrothed to his heir. "My son is very much pleased with his new state, and I am so too, to have chosen such a good daughter-in-law, as I hold this marriage certain to produce very beneficial effects to the Catholic religion, which is my sole aspiration."[[22]]

Not many weeks afterwards, on the 7th October, the King in great trouble writes to the nun—

"I have received your letter, but I confess that I am not in a condition to reply to it, for our Lord has placed upon me a trial through which I can hardly live. Since yesterday my son is oppressed with very extreme fever. It began by severe pains in his body, which lasted all day; and now he is delirious, and we are in such fear that we hope it will turn to smallpox, ... of which the doctors say they see signs. I know, Sor Maria, that I deserve heavy punishments, and that all that may come to me in this life will be insufficient to repay my sins; but I do cry now to the divine mercy of our Lord, and the intercession of His holy Mother; and I beseech you to help with all your strength."

Philip's despair

Three days afterwards, the heart-broken father writes in dull despair that his son had died. "I have lost," he wrote, "my only son, and such a son, as you know he was." And for this pain the consolations of the good woman, though salutary, were weak. Philip bowed his head, and to all outward seeming was resigned to his loss. He did not rail against the decrees of Providence that had left him alone in the world, but his resignation now was a fatalistic hopelessness; for this blow had finally convinced him that the Most High had doomed him to affliction, and his people to suffering untold, solely for his sins. There was no way out of it, even by prayer; and Philip for a time gave up trying to be good.