Glorfindel was born in Tirion sometime during the Noontide of Valinor, and was descended from a house of princes. He followed the House of Fingolfin during the Flight of the Ñoldor, but he took no part in the Kinslaying at Alqualondë.
In exile, Glorfindel fought in the Battle of the Lammoth, as he followed the House of Fingolfin. After the exile, Glorfindel was in the host of Turgon at the Dagor Aglareb. After the battle he followed Turgon to Gondolin, where he was appointed as the Lord of the House of the Golden Flower and one of the captains of the King. He was popular and well-loved by the Gondolindrim.
When Aredhel wished to depart Gondolin to seek the Sons of Fëanor, Turgon appointed Glorfindel, Ecthelion, and Egalmoth as her escorts. They were denied entrance to Doriath, and instead turned north where the escort lost Aredhel near Nan Dungortheb. They later returned to Gondolin without her.
Along with King Turgon, Glorfindel fought in the Nírnaeth Arnoediad, holding the King's flanks as they retreated towards the Pass of Sirion.
In FA 510, the forces of Melkor attacked Gondolin, with the help of Maeglin's treachery. Glorfindel and the last of his followers held the Great Market from the Orcs, in pursuance of ambushing the enemies. However, they themselves were ambushed and fought until a fire-drake arrived. Glorfindel and his people cut their way out, but were pursed by the orcs.
The House of the Harp arrived to help after disobeying their deceitful lord, Salgant.
The House of the Golden Flower regrouped at the Square of the King and was one of the last Houses to fight.
Glorfindel joined Tuor in defending the Square, until Egalmoth arrived and Ecthelion was slain during his fight with Gothmog. When King Turgon was also slain, the Gondolindrim escaped through Idril's Secret Way, with Glorfindel holding the rear manfully and lost more of his followers there.
As they made their escape through Cirith Thoronath, one of the Balrogs came upon the refugees. Glorfindel leapt forward to face the Balrog, while his followers watched from afar. He fended himself from the Balrog's whip and claws, and successfully hewed its iron helm.
At the last moment, he pierced the Balrog's belly and it fell backwards towards the cliff, but it grabbed Glorfindel by his hair and both of them fell into the deep abyss.
His body was later borne up by Thorondor, Lord of Eagles, who flew down into the Abyss to rescue Glorfindel's broken body, returning it to his people who buried him high on the cliffs of the Mountains which surrounded Gondolin.
It was said that yellow flowers (possibly celandine) grew on his mound, despite its rocky location.
Glorfindel's spirit departed to the Halls of Mandos, where he passed a short time. Due to his noble actions that had saved many Elves in the Fall of Gondolin, he was re-embodied and dwelt in Valinor.
Many years later, in SA 1600, Manwë sent him back to Middle-earth as an emissary of the Valar and granted him powers nearly as strong as that of the Maiar's
It is possible that Glorfindel remained for a time in Lindon along with the other noble Elves, such as Gil-galad, Círdan, and Elrond, a descendant of Tuor and Idril.
In the Battle of Fornost, Glorfindel turned the odds against the Witch-king of Angmar and his host. After the battle finished, and the Witch-king had fled, it was Glorfindel who predicted that no mortal man would ever destroy the Witch-king. This prediction was fulfilled a thousand years later at the Battle of the Pelennor Fields, when Éowyn of Rohan and Meriadoc Brandybuck, a hobbit, slew the Witch-king.
A thousand years later, Glorfindel was sent by Lord Elrond to search for Frodo and his companions. He pursued some of the Nazgûl and drew them away from the Ford of Bruinen. He then found and led the company for days stopping only briefly to let the Hobbits rest. When the Nazgul approached again, Glorfindel put Frodo on his white horse Asfaloth, and bade the horse take Frodo to Rivendell.
Asfaloth outran the black horses of the Nazgûl and managed to cross the Ford of Bruinen which led to Rivendell. A severely weakened Frodo, conscious but delirious due to the wound he bore from the Morgul-knife, turned back to defy the Riders who pleaded for him to come with them.
The Nazgûl entered the shallow ford but were there un-horsed and swept away by a torrent of enchanted water which guarded the entrance to Imladris charged with the power of the Half-elven and indeed by Gandalf the Grey.
He later led the injured Frodo and the rest of the company safely to Rivendell.
At the Council of Elrond, Glorfindel sat in a position of honour alongside Elrond and Gandalf. He suggested that the One Ring should be either sent to Tom Bombadil and cast into the depths of the Sea, but Gandalf believed that the One may resurface on land after a hundred or thousand years.
He was briefly considered to be a member of the Fellowship of the Ring, but was later ruled out: his power would be of no use in a mission of secrecy to Mordor.
After the Ring's destruction, Glorfindel, along with Erestor and the sons of Elrond, witnessed the wedding of Aragorn and Arwen. His ultimate fate is not known, but it is reasonable to assume that he eventually sailed to Valinor with the rest of his kin*