As to the process and the death of the Prince, the mystery has not yet been removed, and the field is still open to conjecture. It seems a thankless task to grope in the dark after the truth at a variety of sources; when the truth really exists in tangible shape if profane hands could be laid upon it. The secret is buried in the bosom of the Vatican. Philip wrote two letters on the subject to Pius V. The contents of the first (21st January, 1568) are known. He informed the pontiff that he had been obliged to imprison his son, and promised that he would, in the conduct of the affair, omit nothing which could be expected of a father and of a just and prudent king. The second letter, in which he narrated, or is supposed to have narrated, the whole course of the tragic proceedings, down to the death and burial of the Prince, has never yet been made public. There are hopes that this secret missive, after three centuries of darkness, may soon see the light.—[I am assured by Mr. Gachard that a copy of this important letter is confidently expected by the Commission Royale d'Histoire.]
As Philip generally told the truth to the Pope, it is probable that the secret, when once revealed, will contain the veritable solution of the mystery. Till that moment arrives, it seems idle to attempt fathoming the matter. Nevertheless, it may be well briefly to state the case as it stands. As against the King, it rests upon no impregnable, but certainly upon respectable authority. The Prince of Orange, in his famous Apology, calls Philip the murderer of his wife and of his son, and says that there was proof of the facts in France. He alludes to the violent death of Carlos almost as if it were an indisputable truth. "As for Don Charles," he says, "was he not our future sovereign? And if the father could allege against his son fit cause for death, was it not rather for us to judge him than for three or four monks or inquisitors of Spain?"
The historian, P. Matthieu, relates that Philip assembled his council of conscience; that they recommended mercy; that hereupon Philip gave the matter to the inquisition, by which tribunal Carlos was declared a heretic on account of his connexion with Protestants, and for his attempt against his father's life was condemned to death, and that the sentence was executed by four slaves, two holding the arms, one the feet, while the fourth strangled him.
De Thou gives the following account of the transaction, having derived many of his details from the oral communications of Louis de Foix:
Philip imagined that his son was about to escape from Spain, and to make his way to the Netherlands. The King also believed himself in danger of assassination from Carlos, his chief evidence being that the Prince always carried pistols in the pockets of his loose breeches. As Carlos wished always to be alone at night without any domestic in his chamber, de Foix had arranged for him a set of pulleys, by means of which he could open or shut his door without rising from his bed. He always slept with two pistols and two drawn swords under his pillow, and had two loaded arquebusses in a wardrobe close at hand. These remarkable precautions would seem rather to indicate a profound fear of being himself assassinated; but they were nevertheless supposed to justify Philip's suspicions, that the Infante was meditating parricide. On Christmas eve, however (1567), Don Carlos told his confessor that he had determined to kill a man. The priest, in consequence, refused to admit him to the communion. The Prince demanded, at least, a wafer which was not consecrated, in order that he might seem to the people to be participating in the sacrament. The confessor declined the proposal, and immediately repairing to the King, narrated the whole story. Philip exclaimed that he was himself the man whom the Prince intended to kill, but that measures should be forthwith taken to prevent such a design. The monarch then consulted the Holy Office of the inquisition, and the resolution was taken to arrest his son. De Foix was compelled to alter the pulleys of the door to the Prince's chamber in such a manner that it could be opened without the usual noise, which was almost sure to awaken him. At midnight, accordingly, Count Lerma entered the room so stealthily that the arms were all, removed from the Prince's pillow and the wardrobe, without awakening the sleeper. Philip, Ruy Gomez, the Duke de Feria, and two other nobles, then noiselessly, crept into the apartment. Carlos still slept so profoundly that it was necessary for Derma to shake him violently by the arm before he could be aroused. Starting from his sleep in the dead of night, and seeing his father thus accompanied, before his bed, the Prince cried out that he was a dead man, and earnestly besought the bystanders to make an end of him at once. Philip assured him, however, that he was not come to kill him, but to chastise him paternally, and to recal him to his duty. He then read him a serious lecture, caused him to rise from his bed, took away his servants, and placed him under guard. He was made to array himself in mourning habiliments, and to sleep on a truckle bed. The Prince was in despair. He soon made various attempts upon his own life. He threw himself into the fire, but was rescued by his guards, with his clothes all in flames. He passed several days without taking any food, and then ate so many patties of minced meat that he nearly died of indigestion. He was also said to have attempted to choke himself with a diamond, and to have been prevented by his guard; to have filled his bed with ice; to have sat in cold draughts; to have gone eleven days without food, the last method being, as one would think, sufficiently thorough. Philip, therefore, seeing his son thus desperate, consulted once more with the Holy Office, and came to the decision that it was better to condemn him legitimately to death than to permit him to die by his own hand. In order, however, to save appearances, the order was secretly carried into execution. Don Carlos was made to swallow poison in a bowl of broth, of which he died in a few hours. This was at the commencement of his twenty-third year. The death was concealed for several months, and was not made public till after Alva's victory at Jemmingen.
Such was the account drawn up by de Thou from the oral communications of de Foix, and from other sources not indicated. Certainly, such a narrative is far from being entitled to implicit credence. The historian was a contemporary, but he was not in Spain, and the engineer's testimony is, of course, not entitled to much consideration on the subject of the process and the execution (if there were an execution); although conclusive as to matters which had been within his personal knowledge. For the rest, all that it can be said to establish is the existence of the general rumor, that Carlos came to his death by foul means and in consequence of advice given by the inquisition.
On the other hand, in all the letters written at the period by persons in Madrid most likely, from their position, to know the truth, not a syllable has been found in confirmation of the violent death said to have been suffered by Carlos. Secretary Erasso, the papal nuncio Castagna, the Venetian envoy Cavalli, all express a conviction that the death of the prince had been brought about by his own extravagant conduct and mental excitement; by alternations of starving and voracious eating, by throwing himself into the fire; by icing his bed, and by similar acts of desperation. Nearly every writer alludes to the incident of the refusal of the priest to admit Carlos to communion, upon the ground of his confessed deadly hatred to an individual whom all supposed to be the King. It was also universally believed that Carlos meant to kill his father. The nuncio asked Spinosa (then president of Castile) if this report were true. "If nothing more were to be feared," answered the priest, "the King would protect himself by other measures," but the matter was worse, if worse could be. The King, however, summoned all the foreign diplomatic body and assured them that the story was false. After his arrest, the Prince, according to Castagna, attempted various means of suicide, abstaining, at last, many days from food, and dying in consequence, "discoursing, upon his deathbed, gravely and like a man of sense."
The historian Cabrera, official panegyrist of Philip the Second, speaks of the death of Carlos as a natural one, but leaves a dark kind of mystery about the symptoms of his disease. He states, that the Prince was tried and condemned by a commission or junta, consisting of Spinosa, Ruy Gomez, and the Licentiate Virviesca, but that he was carried off by an illness, the nature of which he does not describe.
Llorente found nothing in the records of the Inquisition to prove that the Holy Office had ever condemned the Prince or instituted any process against him. He states that he was condemned by a commission, but that he died of a sickness which supervened. It must be confessed that the illness was a convenient one, and that such diseases are very apt to attack individuals whom tyrants are disposed to remove from their path, while desirous, at the same time, to save appearances. It would certainly be presumptuous to accept implicitly the narrative of de Thou, which is literally followed by Hoofd and by many modern writers. On the other hand, it would be an exaggeration of historical scepticism to absolve Philip from the murder of his son, solely upon negative testimony. The people about court did not believe in the crime. They saw no proofs of it. Of course they saw none. Philip would take good care that there should be none if he had made up his mind that the death of the Prince should be considered a natural one. And priori argument, which omits the character of the suspected culprit, and the extraordinary circumstances of time and place, is not satisfactory. Philip thoroughly understood the business of secret midnight murder. We shall soon have occasion to relate the elaborate and ingenious method by which the assassination of Montigny was accomplished and kept a profound secret from the whole world, until the letters of the royal assassin, after three centuries' repose, were exhumed, and the foul mystery revealed. Philip was capable of any crime. Moreover, in his letter to his aunt, Queen Catharine of Portugal, he distinctly declares himself, like Abraham, prepared to go all lengths in obedience to the Lord. "I have chosen in this matter," he said, "to make the sacrifice to God of my own flesh and blood, and to prefer His service and the universal welfare to all other human considerations." Whenever the letter to Pius V. sees the light, it will appear whether the sacrifice which the monarch thus made to his God proceeded beyond the imprisonment and condemnation of his son, or was completed by the actual immolation of the victim.
With regard to the Prince himself, it is very certain that, if he had lived, the realms of the Spanish Crown would have numbered one tyrant more. Carlos from his earliest youth, was remarkable for the ferocity of his character. The Emperor Charles was highly pleased with him, then about fourteen years of age, upon their first interview after the abdication. He flattered himself that the lad had inherited his own martial genius together with his name. Carlos took much interest in his grandfather's account of his various battles, but when the flight from Innspruck was narrated, he repeated many times, with much vehemence, that he never would have fled; to which position he adhered, notwithstanding all the arguments of the Emperor, and very much to his amusement. The young Prince was always fond of soldiers, and listened eagerly to discourses of war. He was in the habit also of recording the names of any military persons who, according to custom, frequently made offers of their services to the heir apparent, and of causing them to take a solemn oath to keep their engagements. No other indications of warlike talent, however, have been preserved concerning him. "He was crafty, ambitious, cruel, violent," says the envoy Suriano, "a hater of buffoons, a lover of soldiers." His natural cruelty seems to have been remarkable from his boyhood. After his return from the chase, he was in the habit of cutting the throats of hares and other animals, and of amusing himself with their dying convulsions. He also frequently took pleasure in roasting them alive. He once received a present of a very large snake from some person who seemed to understand how to please this remarkable young prince. After a time, however, the favorite reptile allowed itself to bite its master's finger, whereupon Don Carlos immediately retaliated by biting off its head.