The famous and very powerful count Charles, son of the king of Denmark and King Louis's aunt, succeeded by hereditary right the brave Count Baldwin VII, son of Robert of Jerusalem, and ruled the very populous land of Flanders both vigorously and diligently, proving himself an illustrious defender of God's church, a lavish almsgiver and a notable protector of justice. Discharging the duty of his honour, he sought several times and legitimately to bring to the judgment of his court certain powerful men of low birth who had risen through their wealth, and who were arrogantly trying to extricate their family from his lordship although they were of servile origin. They were the provost of Bruges and his relations, notorious criminals puffed up with pride, who trapped the count most cruelly.
One day Charles came to Brugge and went early in the morning into God's church (St.Donation); he was kneeling on the floor in prayer, holding a prayer book in his hands, when suddenly a certain Borchard, the nephew of the provost Bertulf, a savage fellow, arrived with other members of that wickedest of families and other accomplices in his detestable crime. As Charles was praying and talking with God, Borsiard quietly slipped behind him, unsheathed his sword and gently touched the neck of the prostrate count, so that when the count raised it a little he would make a better target for the unexpected sword, then with one blow he killed the pious man, and thus the serf decapitated his lord.
Borsiard's accomplices in this horrifying murder who were standing around thirsting for Charles' blood, like dogs feasting on abandoned corpses, took pleasure in hacking the innocent man to pieces, particularly rejoicing that they had been able to accomplish the evil deed they had conceived and the wickedness to which they had given birth. As if blinded by their own malice, they heaped iniquity, and massacred all the men of the castle and nobler barons of the count they could find, either in the church or outside in the castle, putting them to the sword in the most wretched way when they were unprepared and unshriven of their sins.
Suger states: "The assassins buried the count in the church itself, fearing that if he were brought out for mourning and burial, the people who were devoted to him both for his glorious life and for his glorious death would be aroused to seek vengeance." Then they turned the church into a brigands' cave, fortified both it and the count's house which was next to it, procured whatever food they could and decided with the utmost arrogance to defend themselves there and to take over the land.
However another source states: " . . . a few of the Counts vassals and dependants came together and buried him in a tomb that had been constructed out of stones and cement upon the floor in the place where he had been killed."
The Flemish barons who had not agree with their actions were shocked by so great and wicked a crime. They wept as they attended the count's obsequies in order to avoid being branded as traitors, and reported it to the lord king Louis, and indeed to everyone, for the news swept across the world. Love of justice and affection for his cousin inspired war by Count Thibaud of Champagne who was in England at that time on behalf of the English king, King Henry I . He crossed courageously into Flanders, intent on using all his resources to punish the wickedest of men most cruelly.
He established as count of Flanders William of Normandy, son of Duke Robert of Jerusalem, who had a claim through ties of blood. Without fear either for the barbarity of the land or for the loathsome family which had engaged in treason, he went down to Bruges, and blockaded the traitors tightly in the church and the tower, preventing them from obtaining any food other than what they had, which by divine assistance now disgusted them because it was unfit for use. For a while he wore them down by hunger, disease and the sword; then they abandoned the church the church and kept only the tower, which also guarded them.
Now they despairing of life the most wicked Borsiard left with the agreement of his companions, hoping to flee the land but found himself unable to do so, though only his own iniquity prevented him. On his return to the castle of one of his intimate friends he was seized by the king's command and suffered exquisite torture in death. Tied to the upper part of a high wheel, exposed naked to the rapacity of crows and other birds of prey, his eyes torn out and his whole face lacerated, pierced by a thousand blows from arrows, lances and spears, he perished miserably and his body was thrown into a sewer.
Bertulf, the planner of the plot, also decided to flee; but when he found he was able to wander around without restriction, he returned through sheer pride; for he asked himself, 'Who am I and what have I done?' So he was captured by his own men, handed over to the king's judgment and condemned to a well-merited and wretched death. They hanged him from a gibbet with a dog and as the dog was struck it took its anger out on Bertulf, chewed his whole face and, horrible to relate, covered him with excrement; so, more miserable than the most miserable of men, he ended his wretched life in perpetual death.
The men the king had besieged in the tower were forced by many hardships to surrender. In front of their relations, Louis had them thrown our one by one from the top of the tower to crush their skulls. One of them called Isaac had been tonsured in a monastery to avoid death; Louis ordered him to be defrocked and hanged on a gibbet. Thus victorious at Bruges, the king rapidly led his army to Ypres, an excellent castle, to take further vengeance on those who had fomented the treason. He sent messengers to the people of Brugge and brought them around to his side by threats and flattery. Then as William the bastard son of Robert the Magnificent, Duke of Normandy, barred his way to Brugge with three hundred knights, half the royal army rushed against him and the other half went off at an angle and entered and occupied the castle by way of its other gate. The king kept it; William lost all claim to Flanders, and was banished. because he had aspired to gain Flanders through treachery, it was right that he should gain nothing whatever in Flanders.
Flanders was washed clean and almost re-baptized by these various forms of revenge and the great outpouring of blood. So having installed William of Ypres as count, the king returned to France, victorious by God's help.