Frostbane

Origin
The Sword Frostbane was forged by Reyenirus Battlehorn at the Magma Forge underneath Red Mountain during his quest to Vvardenfell. Reyenirus Battlehorn used this weapon to banish The Grand Frost Mage to Lyg for 270,000 years.

The Magma Forge it was created in collapsed soon after its creation as punishment to the Forge Bearer for giving such a powerful enchanted weapon to a Normal Colovian Being.

Usage
Reyenirus Battlehorn used the Blade a Single time to banish the Grand Frost Mage from Tamriel during the Frostmarch.

After the Frostmarch, Reyenirus Battlehorn hid Frostbane from Reman II who wished to wield the Weapon himself.

It was Guarded closely by the Elite of the Hosts of the True Horn in Castle Lainlyn, until Lord Kain's Rebellion in which he stole the Sword from Baron Shrike Battlehorn and had his Knights of the True Horn hide it during their migration to Cyrodiil.

Sometime during the construction of Battlehorn Castle, the Frostbane was stolen by an Argonian who wished to use to Murder the Arch-Mage of the Arcane University due to untold reasons. While the Argonian was in possession of the Blade, he was killed by a Dark Brotherhood assassins, and the Blade found its way into the Vault of the Gray Fox. When the Hero of Kvatch became the Gray Fox, he discarded it without knowledge of its abilities, and its current whereabouts since then are unknown.