The chief hero of the Geste de Garin de Monglane. Guillaume d'Orange, translated into English as William of Orange, was the central figure of the Geste de Garin de Monglane.

Guillaume was the son of , and great grandson of Garin de Monglane.

The legendary Guillaume was based on historical figure, the count of Toulouse, who served as a military leader of Charlemagne.

Renaud is the hero of epic named after him, Chanson de Renaud de Montauban, or Les Quatre Fils Aymon. Renaud was a son of Aymon de Dordogne, and brother of Alard, Guiscard, and Richard. Amyon was one of the sons of Doon de Mayence.

According to the Italian romance, Orlando Furioso (written by Ludovico Ariosto), he was called Rinaldo, and he was brother of a sister, named Bradamante. In this work, he was also seen as cousin of Orlando (Roland). Both Rinaldo and Bradamante played prominent role in Orlando Furioso.

He was the owner of magical horse, Bayard, extremely loyal to Renaud, and strong enough to carry all four brothers.

In Renaud de Montauban, Renaud had killed Charlemagne's nephew, earning him disfavour of the king. Renaud and his brothers fled to Montessor, a fortress on a rock. Charlemagne waged war against the four brothers, besieging Montessor. Their father, Aymon took the king's side. Charlemagne only agreed to pardon the four sons of Aymon, if they go and fight in a Crusade at Jerusalem as banishment. Renaud must also give up his horse, Bayard.

Charlemagne didn't like the horse's unwavering loyalty to the former master, so Charlemagne orders his men to drown the horse, by tying the horse to heavy millstone, which was tossed into a river. Bayard, however, escaped and eventually found its way to Renaud.

After the Crusade, Renaud went to Cologne, where he decided to retire, turning toward life of religion. He began by helping the builders to built a cathedral for no wages. Some builders were jealous, possibly because of his strength, so they murdered him, and dumped his body in the Rhine River. His body was recovered at Dortmund, where he was buried.

In Orlando Furioso, Rinaldo became Orlando's rival, because they both fell in love with Saracen princess from Africa, named Angelica.