Narsil was made in the First Age by Telchar, the most renowned of the Dwarf-smiths of Nogrod in the Blue Mountains. The blade shone with the light of the Sun and the Moon.

Nothing is known about the sword's original owner or its early history. Narsil became the sword of Elendil, who escaped the downfall of Numenor and founded the Kingdoms of Gondor and Arnor in Middle-earth. Elendil wielded Narsil during the War of the Last Alliance, and the sword filled Sauron's forces with fear.

Anduril is the reforged Narsil, and is used by Aragorn, King of Gondor. The inscription down the length of the blade on both sides in the Middle-Earth language of Quenya, written in the runes of Eregion, that say "Nanye Anduril i ne Narsil i macil Elendilo. Lercuvanten i mali Mordoreo." This translates to "I am Anduril who was Narsil, the sword of Elendil. Let the thralls of Mordor flee me."