Dor-Cúarthol, the "Land of Bow and Helm", was a name given to the area Talath Dirnen around Amon Rûdh, between Teiglin and the edges of Doriath. The name comes from Beleg's great bow and the Helm of Hador borne by Túrin whose outlaw band protected that land from Orcs between F.A. 487 and 489.
Amon Rûdh was the old home of a family of Petty-dwarves, Mîm and his sons, when Túrin and his outlaws came requesting to stay, threatening the Dwarf with his life. One day in the midst of winter, Beleg, having been seeking out his old friend, brought to him the Helm of his ancestors, and joined the outlaws. Together, the Two Captains defended that region against the Orcs of Morgoth. Túrin took a new name, Gorthol, from the dreadful Helm he was wearing.
The rumour that the Two Captains who fell in Dimbar rose again, travelled to all Beleriand and their deeds were heard in Menegroth, Nargothrond and Gondolin. Many leaderless and dispossessed wanderers took heart and came to seek them. The Orcs didn't dare to enter it, afraid of the hidden terror watching from the hill.
But the fame of the Two Captains also reached Angband, and perceiving that "Gorthol" was truly Túrin the son of Húrin, Morgoth sent his spies to watch the lands around this hill. Mîm eagerly betrayed the outlaws to the Orc captain. The outlaws were routed, Beleg was left for dead, and Túrin was captured and led away to the north.