Now each of the four sons had his own fashion of fighting. Renault fought best on horseback, and to him Maugis son of Buves brought a great horse named Bayard ("Beiaard" in Flemish) of magic origin, possessed of demoniac powers, among which was the ability to run like the wind and never grow weary. Here in this stronghold the four sons of Aymon dwelt, making occasional sallies against the vassals of Charlemagne, until at length the Emperor gathered a mighty force of soldiers and horses and engines and scaling ladders, and, surrounding the stronghold, at length succeeded in capturing it. Tradition says that among Charlemagne's retinue was Aymon himself, and intimates that it was by the father's treachery that the four mighty sons were almost captured, but at any rate the great castle of Montfort was reduced to ashes and ruin, and only the fact of Renault's taking the other brothers on the back of the wondrous horse Bayard saved them all from the Emperor's fury. So they escaped into Gascony, where they independently attacked the Saracens and drove them forth and extended their swords to the King of Gascony, Yon, who treacherously delivered them in chains over to Charlemagne. These chains they broke and threw in the Emperor's face, fighting their way to freedom with their bare hands. History thereafter is silent as to their end. Of Renault it is known only that he became a friar at Cologne, where his skill and strength were utilized by the authorities in building the walls, and that one day while at work, some masons whom he had offended crept up behind him and pushed him off a great height into the River Rhine, and thus he was drowned. Years afterward the Church canonized him, and in Westphalia at Dortmund may be seen a monument erected in his memory extolling his prowess, his deeds, and his strength. As to the great and magical horse Bayard, the chronicle says that, captured finally by Charlemagne's soldiers and brought before him, the Emperor deliberated what he should do with it, since it refused to be ridden. Finally he ordered that the largest mill stone in the region should be made fast to its neck by heavy chains, and that it should then be cast into the River Meuse. Bayard contemptuously shook off the heavy stone and with steam pouring from his nostrils, gave three neighs of derision and triumph and, climbing the opposite bank, vanished into the gloom of the forest where none dared follow. Of the immortality of this great horse history is emphatic and gravely states that, for all that is known to the contrary, he may still be at large in the Ardennes, but that "no man has since beheld him."