How William, his brother-in-law, committed treason against Guy at Roche-Guyon; of Guy's death and the prompt revenge taken against William
On a sharp promontory above the bank of the great river Seine there stands a frightening and looming castle called la Roche-Guyon, carved out of a high rock so as to make its outside invisible. The skilled hand of hand of its builder had created, by breaking the rock in the slope of the mountain, living quarters of good size entered through a small and mean hole. One would take it for a seer’s grotto in which the oracles of Apollo are produced or the cave of which Lucan spoke: ‘For although the prophet of Thessaly did violence to the fates, it is not known whether, when she looked on the shadows of the Styx, she had called them up, or had descended to find them.’ Perhaps it is the route to the underworld.
The owner of this wicked fortress, despised equally by gods and men, was Guy, a young man imbued with goodness, breaking the evil tradition of his ancestors, who had decided to lead an honourable life, free from their wretched hunger for rapacity. But overcome by the evil inherent in that ill-fated place, he was most wickedly betrayed by his sinful father-in-law and beheaded, thus losing through his untimely death both the place and his life. His brother-in-law William, a Norman by birth, was a traitor without equal. He passed for Guy’s closest and most intimate friend, but he ‘travailed with wickedness and hath conceived mischief.  At dawn one Sunday, he found the opportunity for his crime. He came early to the church in a crevice of the rock next to Guy’s home, with the more devout worshippers. But he was unlike them in wearing mail beneath his cloak and being accompanied by a handful of traitors. While the others were praying he pretended to do so for a little as he calculated how to get to Guy. Then he flung himself at the entrance through which Guy was hastily coming into the church, drew his sword, and with his appalling companions gave himself up to the frenzy of his hatred; Guy was careless and would have smiled at him had he not seen the sword; William struck him, slew him and left him to perish.
At the sight, his noble wife was bemused, tore her cheeks and hair like a woman distracted, rushed to her husband, careless of the danger, and threw herself on his body crying: ‘Vile murderers, slay me in my misery, for I deserve death more than he did.’ Lying on her husband’s body stopping the blows and wounds aimed at him by the swordsmen, she asked, ‘O dearest husband, how did you injure these men? Were you not, as brothers-in-law, the closest of friends? What is this madness? You are consumed by fury!’ When they dragged her off by her hair, her whole body was hacked, wounded and bloody. They murdered her husband in the most appalling way and then, finding her children, they killed them by dashing their heads against the stones with wickedness worthy of Herod.
While they revelled in frenzy here, there and everywhere, the prostrate woman raised her wretched head, saw her husband’s beheaded corpse, and seized by love, despite her weakness she dragged her blood-soaked self across the floor like a serpent to her dead body and, as best she could, kissed him as if he were alive, then broke into a mournful chant, making her grief the best possible sacrificial offering for the dead. ‘O dearest husband, what have you left me? Surely your loving behaviour towards me did not deserve this? Surely this is not the proper complement to your rejection of your father’s, grandfather’s and great grandfather’s evil ways? Is this what you get for not plundering your neighbours and the poor, even though there was want at home?’ And no-one could separate her half-dead body from her husband’s corpse, both soaked in the same blood.
But at least, after he had exposed them to public view as if they were pigs, the wicked William, sated in human blood like a wild animal, allowed his rage to subside. He appreciated the rock’s strength, and somewhat later began to consider how he could most forcefully plunder roundabout, how he could at will strike fear into the hearts of the French and Normans. Then he put his mad head out of the window and called the inhabitants of the land, and ignorant of any good, he promised them evil if any adhered to him. Not one single man came over to him.
But in the morning the news of such a great crime spread not only in the neighbourhood but also to remote places. The men of the Vexin, vigorous and skilled in arms, were much disturbed by it and, each according to his strength collected together an army of knights and foot-soldiers. Fearing lest Henry, the most powerful king of the English, should assist the traitors, they hastened to the rock, posted large numbers of knights and foot-soldiers around the slope to stop anyone from going in or out, and to prevent help coming, they blocked the route to Normandy with the bulk of the army. Then they sent to King Louis news of the plot and a request for orders.
Drawing on his royal power, Louis ordered that the plotters be punished by the most long-drawn out and shameful of deaths, and promised help if they needed it. As the army surrounded William for days, growing larger each day, that wicked man began to be seized by fear. Having considered what he had done at the devil’s bidding, on the devil’s advice he summoned several of the noblest among the men of the Vexin and, in order to remain at peace on the rock, he offered them an alliance, swearing to serve the king of France most faithfully, and making many other promises. They rejected this and, intent on vengeance against the traitor whose courage was already failing, they pressed him so hard that he agreed to hand over to them the fortress he had seized, on condition that they swore to allow him some land and security in which to withdraw to it. After this arrangement had been sworn to, a few or more French were received in the castle.
The question of the land delayed their departure until the next day; then in the morning some others besides those who had sworn entered, then others followed them; and those outside set up a great roar, demanding that the traitors be taken out, or that those who sheltered them be condemned to the same fate as the traitors themselves. Those who had sworn struggled against both their rashness and fear and resisted. Those who had not sworn rushed against them and attacked them at sword-point piously murdering those impious traitors mutilating some, painfully disembowelling others and tortured them with every kind of cruelty, thinking themselves too kind. There can be no doubt that the hand of God exacted this swift vengeance. Men were thrown out of the windows dead or alive, bristling with numerous arrows like hedgehogs. They waved about in the air on the points of the lances, as if the very earth had rejected them. For the unparalleled deed of William they discovered a rare vengeance for he who in life had been heartless had his heart cut out of his dead body. When they had taken it from his entrails, all swollen with fraud and iniquity, they put it on a stake and set it up for many days in a fixed place to demonstrate the punishment for crime.
His body and those of some of his companions, were placed on hurdles tied with cords and ropes, and sent sailing down the Seine so that, if nothing stopped them floating down to Rouen, the Normans should see the punishment incurred by his crime, and also so that those who had briefly fouled France with their stink should in death continue to foul Normandy, their native soil.
 La Roche-Guyon was of some strategic importance as it lay on the frontier between the lands of England and France. It is on the north bank of the Seine a few miles upstream from its junction with the Epte, about forty-two miles north-west of Paris. Suger’s strong language immediately alerts the reader to the evil that is to follow.
 Lucan De bello civili, VI, 651-53
 In 1097, Guy, lord of La Roche-Guyon and Veteuil sold his castles to the English for gold. Suger suggests that this Guy could have been his son by using the term ‘adolescens’. He was descended from the counts of Meulan and was their vassal. This may account for his involvement in the Vexin wars in the late 1090s with Robert of Meulan supporting William Rufus: see ibid, Barlow, Frank, William Rufus, p. 379.
 Ibid, Molinier, Auguste, (ed.), Vie de Louis le Gros par Suger, p. 53 no 4 discussed the marital relationship between Guy and William suggesting that while it is possible that the murderer killed his own sister who was married to Guy, it is more likely that William was married to Guy’s sister. However, in the title of the chapter William is called the brother-in-law of Guy but here he is Guy’s father-in-law and then two lines later Suger uses the term ‘gener’ that can be translated as either ‘son-in-law’ or ‘brother-in-law’. The problem may be overcome if Guy’s unnamed father-in-law planned the murder while his son William, Guy’s brother-in-law carried it out. Even so, the precise nature of the story remains unclear and Suger’s lack of clarity suggests that he did not revise the chapter.
 Psalm VII, 14
 The question is whether this refers to twilight or dawn as the term can mean either. In his description of events after the murder, Suger does not make any allusion to the darkness of the night. There are a number of parallels between the events narrated in this chapter and the later murder of Charles the Good in chapter 30, which also occurred in a church, and its results.
 Ibid, Molinier, Auguste, (ed.), Vie de Louis le Gros par Suger, p. 53 no 1 argued that the drama at La Roche-Guyon took place in 1110 or 1111. Ibid, Luchaire, Louis VI le Gros, Annales de son vie et de son règne, n° 72 suggests that events took place in May 1109. However, the murder took place a little time after the meeting at Les-Planches-de-Neaufles. Henry I had returned to England and did not return until 13th June 1111.
 It is difficult to explain why Suger included this chapter in his narrative in the light of Louis’ failure to involve himself personally beyond this. Louis VI allowed the knights in the Vexin to deal with the murderers because he is occupied in another part of his lands, perhaps at the siege of Le Puiset or he may have been involved in preparations for an expedition to Barcelona. It is interesting to see Louis standing off, particularly in view of possible intervention by Henry.