The Man Túrin Turambar and the Elf Beleg Strongbow were friends and companions from the time of Túrin's fostering in Doriath. After Túrin departed from that land, Beleg later sought him out and joined him to found the Land of Bow and Helm, a bulwark against the Orcs ravaging the western lands of Beleriand.

That land would not survive for long: Beleg and Túrin, the Bow and Helm, were betrayed to the Orcs. Túrin was captured and carried away, while Beleg was left for dead on the heights of Amon Rúdh. Beleg recovered and set out in pursuit of his friend, eventually catching the Orcs in the dark forests of Taur-nu-Fuin in the depths of a thunderstorm. As lightning flashed, Beleg was able to rescue his senseless friend, but when Túrin awakened he momentarily mistook Beleg for one of his captors, and slew the Elf with his own sword.

When he realised what he had done, Túrin was struck dumb with horror. It was only long afterward, being healed by the waters of Eithel Ivrin, that he was able to put his grief into words. He composed a song of lament for his friend, which he named Laer Cú Beleg, or the Song of the Great Bow, in memory of the famed archer who had been his lifelong friend.