GlamdringGlamdring - It was the sword of Turgon, founder of Gondolin, although it played a much greater role in the Third Age, under its new owner, Gandalf the Grey.  After the fall of Gondolin, it passed out of knowledge until it was discovered among a trolls' hoard in the Trollshaws between Weathertop and Rivendell.  It was found alongside its twin sword, Orcrist the "Goblin-cleaver".

 

"Elrond knew all about runes of every kind.  That day he looked at the swords they had brought from the trolls' lair, and he said: 'These are not troll make.  They are old swords, very old swords of the High Elves of the West, my kin.  They were made in Gondolin for the Goblin wars (Battles of Beleriand).  They must have come from a dragon's hoard or goblin plunder, for dragons and goblins destroyed that city many ages ago (spoiler alert)...This Gandalf, was Glamdring, Foehammer that the king of Gondolin once wore.  Keep them well!'" ~The Hobbit, chap. III (A Short Rest)