Belthronding was a mighty bow, made of black yew-wood, that was carried by the most mighty archer of the First Age, Beleg Strongwbow of Doriath. To it he owed his own epithet, 'Strongbow'.

With it, he long defended the borders of King Thingol, and when he left Doriath in search of his friend Túrin, he took it with him. When he found him, together, from the halls of Mîm in Amon Rûdh, they founded the realm of Dor-Cúarthol - the Land of Bow and Helm - with him being the Bow.

When the pair were betrayed to the Orcs, Beleg went to free his friend, but in a tragic turn of fate Túrin mistook him for a foe, and slew him, overcome with grief, Túrin dug a grave for Beleg's body, and he buried Belthronding beside its late owner.