While looking up something else, my eye was caught by an entry on Roland's sword, which according to Brewer's is fabled to have once belonged to Hector, the prince of Troy. He acquired this fantastic sword from a Icelandic giant called Jutmundus from whom he also won his horn Oliphant which may have belonged to Alexander the Great but I do not know how Jutmundus acquired these treasures. The ogres from The Hobbit are now dancing around in the back of my mind. Inspiration? Probably.
This addition to the myth does not occur in The Song of Roland; it is probably from Orlando Furioso, a 16th century poem by Ludovico Ariosto. I do not own a copy of this book or its predecessor Orlando Innamorato but I do own a copy of The Illiad and I could not see what happened to Hector's sword when Achilles killed him. Presumably Achilles took it and Hector's armor since Hector's body was wrapped in cloth to be given back to his father. It could also have been the sword that Hector gave to Ajax and with which Ajax killed himself but Homer does not name this sword.
Brewer's also states that Durendal had been hurled into a poisonous stream to prevent it from falling in to unworthy hands but this differs from the account in The Song of Roland. There, Roland lays down to die with his sword underneath him and, when Charlemagne finds Roland's body, he gives the sword and the Oliphant to his men Rabel or Guineman but does not state who received which item.
Brewer's does offer a meaning for the name of Durendal: it states that the name probably comes from the Latin word "durare", that is "to last" or "endure". I like it.