Cortana with its current owner, Emma
|Creator:||Wayland the Smith|
|Notable past owner/s:|| Jonah Carstairs|
|Current owner/s:||Emma Carstairs|
|“||I am Cortana, of the same steel and temper as Joyeuse and Durendal.||”|
–Inscription on the blade
Cortana is a shortsword that has been passed down through many generations of the Carstairs family, having been in the family for over a hundred years.
Cortana is a shortsword with a simple and bare blade, save for the inscription, which runs down the metal of the blade and describes its legendary forging.
While it was in Elias' possession, the sword was in a scabbard covered in intricate designs of leaves and runes, the same design that covered the hilt.
Cortana is, according to Will Herondale, of legend born. Forged by the first Shadowhunter weapons maker, Wayland the Smith, it has a feather from the wing of the Angel in its hilt, and is made of the same steel as Joyeuse, Charlemagne's sword, and Durendal, Roland's sword.
Jonah Carstairs inherited the family sword, presumably from his own father. Before his death, he instructed his brother, Elias, to give the short sword to his son, Jem, when he turns 18. However, upon finding out that Jem had become a Silent Brother and can no longer accept gifts, Elias decided to give the sword to Will, Jem's parabatai. Offended by how Elias seemed to be referring to Jem as if he were dead, Will refused the gift. After he stormed off, Tessa Gray suggested to Elias that if he decides to have his own children, he should give the sword to them. Elias took Tessa's advice into consideration and eventually had his own children, to whom he passed the sword onto.