Known by another name at first
Then renamed by he of the third and the first
Its accidents spoke of its black thirst
But too late was its nature seen to be accursed
Gurthang
Gurthang was the sword of Túrin Turambar, reforged from Anglachel the sword wielded by Beleg Cúthalion when Túrin slew him in a tragic turn of events.
Tolkien Gateway: Gurthang