When Captain de Nançay arrived so opportunely, he was leaving the King's chamber, whither he had conducted Henry of Navarre and the Prince of Condé. The tumult and excitement had worked Charles up to such a pitch of fury that the lives of the princes were hardly safe. But they were gentlemen, and their first words were to reproach the King for his breach of faith. Charles bade them be silent—"Messe ou mort"—("Apostatize or die"). Henry demanded time to consider; while the Prince boldly declared that he would not change his religion: "With God's help it is my intention to remain firm in my profession." Charles, exasperated still more by this opposition to his will, angrily walked up and down the room, and swore that if they did not change in three days he would have their heads. They were then dismissed, but kept close prisoners within the palace.

The houses in which the Huguenots lodged, having been registered, were easily known. The soldiers burst into them, killing all they found, without regard to age or sex, and if any escaped to the roof they were shot down like pigeons. Daylight served to facilitate a work that was too foul even for the blackest midnight. Restraint of every kind was thrown aside, and while the men were the victims of bigoted fury, the women were exposed to violence unutterable. As if the popular frenzy needed excitement, Marshal Tavannes, the military director of this deed of treachery, rode through the streets with dripping sword, shouting: "Kill! Kill! Bloodletting is as good in August as in May." One would charitably hope that this was the language of excitement, and that in his calmer moods he would have repented of his share in the massacre. But he was consistent to the last. On his death-bed he made a general confession of his sins, in which he did not mention the day of St. Bartholomew; and when his son expressed surprise at the omission, he observed, "I look upon that as a meritorious action, which ought to atone for all the sins of my life."

The massacre soon exceeded the bounds upon which Charles and his mother had calculated. They were willing enough that the Huguenots should be murdered; but the murderers might not always be able to draw the line between orthodoxy and heresy. Things were fast getting beyond all control; the thirst for plunder was even keener than the thirst for blood. And it is certain that among the many ignoble motives by which Charles was induced to permit the massacre, was the hope of enriching himself and paying his debts out of the property of the murdered Huguenots. Nor were Anjou and others insensible to the charms of heretical property. Hence we find the provost of Paris remonstrating with the King about "the pillaging of the houses and the murders in the streets by the guards and others in the service of his majesty and the princes." Charles, in reply, bade the magistrates "mount their horses, and with all the force of the city put an end to such irregularities, and remain on the watch day and night." Another proclamation, countersigned by Nevers, was issued about five in the afternoon, commanding the people to lay down the arms which they had taken up "that day by the King's orders," and to leave the streets to the soldiers only—as if implying that they alone were to kill and plunder.

The massacre, commenced on Sunday, was continued through that and the two following days. Capilupi tells us, with wonderful simplicity, "that it was a holiday, and therefore the people could more conveniently find leisure to kill and plunder." It is impossible to assign to each day its task of blood; in all but a few exceptional cases, we know merely that the victims perished in the general slaughter. Writing in the midst of the carnage, probably not later than noon on the 24th, the nuncio Salviati says: "The whole city is in arms; the houses of the Huguenots have been forced with great loss of life, and sacked by the populace with incredible avidity. Many a man to-night will have his horses and his carriage, and will eat and drink off plate, who had never dreamed of it in his life before. In order that matters may not go too far, and to prevent the revolting disorders occasioned by the insolence of the mob, a proclamation has just been issued, declaring that there shall be three hours in the day during which it shall be unlawful to rob and kill; and the order is observed, though not universally. You can see nothing in the streets but white crosses in the hats and caps of everyone you meet, which has a fine effect!" The nuncio says nothing of the streets encumbered with bleeding corpses, nothing of the cart-loads of bodies conveyed to the Seine, and then flung into the river, "so that not only were all the waters in it turned to blood, but so many corpses grounded on the bank of the little island of Louvre that the air became infected with the smell of corruption." The living, tied hand and foot, were thrown off the bridges. One man—probably a rag-gatherer—brought two little children in his creel, and tossed them into the water as carelessly as if they had been blind kittens. An infant, yet unable to walk, had a cord tied round its neck, and was dragged through the streets by a troop of children nine or ten years old. Another played with the beard and smiled in the face of the man who carried him; but the innocent caress exasperated instead of softened the ruffian, who stabbed the child, and with an oath threw it into the Seine. Among the earliest victims was the wife of the King's plumassier. The murderers broke into her house on the Notre-Dame bridge, about four in the morning, stabbed her, and flung her still breathing into the river. She clung for some time to the wooden piles of the bridge, and was killed at last with stones, her body remaining for four days entangled by her long hair among the woodwork. The story goes that her husband's corpse, being thrown over, fell against hers and set it free, both floating away together down the stream. Madeleine Briçonnet, the widow of Theobald of Yverni, disguised herself as a woman of the people, so that she might save her life, but was betrayed by the fine petticoat which hung below her coarse gown. As she would not recant, she was allowed a few moments' prayer, and then tossed into the water. Her son-in-law, the marquis Renel, escaping in his shirt, was chased by the murderers to the bank of the river, where he succeeded in unfastening a boat. He would have got away altogether but for his cousin Bussy d'Amboise, who shot him down with a pistol. One Keny, who had been stabbed and flung into the Seine, was revived by the reaction of the cold water. Feeble as he was he swam to a boat and clung to it, but was quickly pursued. One hand was soon cut off with a hatchet, and as he still continued to steer the boat down the stream, he was "quieted" by a musket-shot. One Puviaut, or Pluviaut, who met with a similar fate, became the subject of a ballad.

Captain Moneins had been put into a safe hiding-place by his friend Fervacques, who went and begged the King to spare the life of the fugitive. Charles not only refused, but ordered him to kill Moneins if he desired to save his own life. Fervacques would not stain his own hands, but made his friend's hiding-place known.

Brion, governor of the young Marquis of Conti, the Prince of Condé's brother, snatched the child from his bed, and, without stopping to dress him, was hurrying away to a place of safety, when the boy was torn from his arms, and he himself murdered before the eyes of his pupil. We are told that the child "cried and begged they would save his tutor's life."

The houses on the bridge of Notre-Dame, inhabited principally by Protestants, were witnesses to many a scene of cruelty. All the inmates of one house were massacred, except a little girl, who was dipped stark naked in the blood of her father and mother and threatened to be served like them if she turned Huguenot. The Protestant booksellers and printers were particularly sought after. Spire Niquet was burned over a slow fire made out of his own books, and thrown lifeless, but not dead, into the river. Oudin Petit fell a victim to the covetousness of his son-in-law, who was a Catholic bookseller. Rene Bianchi, the Queen's perfumer, is reported to have killed with his own hands a young man, a cripple, who had already displayed much skill in goldsmith's work. This is the only man whose death the King lamented, "because of his excellent workmanship, for his shop was entirely stripped."

Mezeray writes that seven hundred or eight hundred people had taken refuge in the prisons, hoping they would be safe "under the wings of Justice"; but the officers selected for this work had brought them into the fitly named "Valley of Misery," and there beat them to death with clubs and threw their bodies into the river. The Venetian ambassador corroborates this story, adding that they were murdered in batches of ten. Where all were cruel, some few persons distinguished themselves by especial ferocity. A gold-beater, named Crozier, one of those prison-murderers, bared his sinewy arm and boasted of having killed four thousand persons with his own hands. Another man—for the sake of human nature we would fain wish him to be the same—affirmed that unaided he had "despatched" eighty Huguenots in one day. He would eat his food with hands dripping with gore, declaring "that it was an honor to him, because it was the blood of heretics." On Tuesday a butcher, Crozier's comrade, boasted to the King that he had killed one hundred fifty the night before. Coconnas, one of the mignons of Anjou, prided himself on having ransomed from the populace as many as thirty Huguenots, for the pleasure of making them abjure, and then killing them with his own hand, after he had "secured them for hell."

About seven o'clock the King was at one of the windows of his palace, enjoying the air of that beautiful August morning, when he was startled by shouts of "Kill, kill!" They were raised by a body of guards, who were firing with much more noise than execution at a number of Huguenots who had crossed the river—"to seek the King's protection," says one account; "to help the King against the Guises," says another. Charles, who had just been telling his mother that "the weather seemed to rejoice at the slaughter of the Huguenots," felt all his savage instincts kindle at the sight. He had hunted wild beasts; now he would hunt men, and, calling for an arquebuse, he fired at the fugitives, who were fortunately out of range. Some modern writers deny this fact, on the ground that the balcony from which Charles is said to have fired was not built until after 1572. Were this true, it would only show that tradition had misplaced the locality. Brantome expressly says the King fired on the Huguenots—not from a balcony, but—"from his bedroom window." Marshal Tesse heard the story, according to Voltaire, from the man who loaded the arquebuse. Henault, in his Abrégé chronologique, mentions it with a "dit-on" and it is significant that the passage is suppressed in Latin editions. Simon Goulart, in his contemporary narrative, uses the same words of caution.

Not many of the Huguenot gentlemen escaped from the toils so skilfully drawn round them on that fatal Saturday night: yet there were a few. The Count of Montgomery—the same who was the innocent cause of the death of Henry II—got away safe, having been forewarned by a friend who swam across the river to him. Guise set off in hot pursuit, and would probably have caught him up had he not been waiting for the keys of the city gate. Some sixty gentlemen, also, lodging near him in the Faubourg St. Germain, were the companions of his flight.