NoldorIn the works of J. R. R. Tolkien, the Noldor (meaning Those with knowledge) are those Elves who initially followed Finwë as their King. They speak Quenya. They are also known as Deep Elves, Golodhrim and Golug. Single is Noldo and the adjective is Noldorin.
Warning: Wikipedia contains spoilers
The Noldor are accounted the greatest of the Elves in lore and smithcraft. Fëanor was the greatest of their craftsmen, and their second and briefest-reigning High King. When Melkor killed Finwë and stole the Silmarils, the Noldor pursued him to Middle-earth and waged war against him.
The Noldor went to Middle-earth without the permission of the Valar and they destroyed the port of Alqualondë, which was built by the Teleri and committed the so-called Kinslaying. The departure of the Noldor out of the Undying Lands marked the beginning of the First Age. The Noldor were soon attacked, and when Fëanor rode too far from his bodyguard during the Battle under the Stars (1st Age 1) he was slain by Balrogs.
The royal houses of the Noldor were feuding, but Fingon saved Maedhros from Morgoth's evil and the feud was settled. Maedhros was due to succeed Fëanor, but he regretted his part of the Kinslaying and left the High Kingship of the Noldor to his uncle Fingolfin, who became the third High King of the Noldor.
Fingolfin reigned long in the land of Hithlum, and his younger son Turgon built the hidden kingdom Gondolin. Fingolfin's reign was marked by warfare against Morgoth and in 75 1st Age the Noldor started the siege of Angband, the great fortress of Morgoth. But in 455 1st Age the siege was broken by Morgoth and Fingolfin rode to Angband and challenged Morgoth to single combat with him. He dealt Morgoth seven wounds but perished, and he was succeeded by his eldest son Fingon, who became the fourth High King of the Noldor.
In 471 1st Age he ordered an all out attack on Morgoth and this led to the Nirnaeth Arnoediad, the Battle of Unnumbered Tears. The battle was a great disaster for the Noldor and Fingon the Valiant was slain. He was succeeded by his brother Turgon.
Turgon had withdrawn to Gondolin and tried to keep the kingdom hidden from Morgoth. He was so successful that even most of the Noldor didn't know where it was located, and he was High King in name alone. In 510 1st Age Gondolin was betrayed by Maeglin and sacked. During the attack Turgon was killed; however many of his people escaped and found their way south. Turgon's nephew Gil-galad became the sixth and last High King of the Noldor.
Finally the Valar came down to Middle-earth and in 583 1st Age the so-called War of Wrath was fought and Morgoth was cast into the Void. But Beleriand sank into the sea, except for Lindon. The defeat of Morgoth marked the start of the Second Age.
Gil-galad founded a new kingdom at Lindon, and ruled throughout the Second Age, longer than any of the High Kings except for Finwë. But at the end of the Second Age his allies in Númenor lost their island and Elendil, Isildur and Anárion came to Middle-earth and they founded the kingdoms of Arnor and Gondor.
Sauron by this time had replaced his master Morgoth as the Dark Lord of Evil. He had deceived the Númenoreans and managed to return from Númenor to his kingdom of Mordor. He hated Elendil and attacked Gondor before it could take root. But he didn't count on the growing power of Gil-galad. Both Elendil and Gil-galad set out for Mordor and defeated Sauron in the Battle of Dagorlad and finally in the Siege of Barad-dûr. There Gil-galad perished, and so ended the High Kingship of the Noldor. No new High King was elected, as although Eärendil and Elrond both had good claims on it, neither claimed the throne.