Cortain
Cortain (also spelled Courtain, Cortana, Curtana, Cortaine or Corte) is the short sword of the legendary Ogier the Dane, a paladin of Charlemagne's court. The name is the accusative case declension of Old French corte, meaning "short".
According to Chevalerie Ogier, the sword was lent and formally given by the courteous Saracen Caraheu; it originally belonged to Brumadant le sauvage, and tempered twenty times by the sword smith Esurable, who broke it after testing it 20 times on a marble block, then recrafted it as a shorter sword, hence named "Short".
But according to Renaud de Montauban, it was named "short" because a half-foot of its tip chipped off when tried on a testing-stone at Aix-la-Chapelle castle, and a somewhat similar account is given in the Old Norse Karlamagnús saga. Arthurian literature (Prose Tristan) claims it used to be the broken-tipped sword belonging to Sir Tristan.
An actual sword purported to be Ogier's Cortain was displayed at the monastery of St. Faro (Abbaye Saint-Faron de Meaux), and after the said monastery was razed in the 18th century, there had been a frantic search for the whereabouts of the sword (cf. § Purported swords).