Some legends claim Joyeuse was forged to contain the Lance of Longinus within its pommel; others say the blade was smithed from the same materials as Roland's Durendal and Ogier's Curtana.

The 11th century Song of Roland describes the sword:

[Charlemagne] was wearing his fine white coat of mail and his helmet with gold-studded stones; by his side hung Joyeuse, and never was there a sword to match it; its colour changed thirty times a day.

Some seven hundred years later, Bulfinch's Mythology described Charlemagne using Joyeuse to behead the Saracen commander Corsuble as well as to knight his comrade Ogier the Dane. The town of Joyeuse, in Ardèche, is supposedly named after the sword: Joyeuse was allegedly lost in a battle and retrieved by one of the knights of Charlemagne; to thank him, Charlemagne granted him an appanage named Joyeuse. Baligant, a general of the Saracens in The Song of Roland, named his sword Précieuse, in order not to seem inferior to Charlemagne.

More Info: en.wikipedia.org