Fëanor, also known as Curufinwë, is one of the more famous Elves in the Silmarillion. Born in Valinor, he was the eldest son of Finwë, King of the Noldor, through his first wife, Míriel Serindë. It is reported that his birth took away so much of his mother's life force that she died after a few months. Not only that, but Miriel refused to reincarnate from the Halls of Mandos, allowing Finwë to take a new wife, Indis. This sowed a seed of jealousy in young Fëanor, which intensified when Indis gave birth to several children—his half-siblings.
Later, he would marry Nerdanel, daugther of the smith Mahtan. Nerdanel went on to bear him seven sons: Mahedros, Maglor, Celegorm, Curufin, Caranthir, Amrod, and Amras. It is said that only she was able to influence Fëanor when others could not, and even then, only for a time. Fëanor was a great smith himself, and his creations included the Palantiri and the Silmarils, the latter being three jewels filled with the light of the Two Trees of Valinor.
When said jewels were stolen by Morgoth, Fëanor launched an all-out war to get them back, in which he was accompanied by his sons, his half-brother Fingolfin, and his nephews and nieces. While some of these turned back before they reached Middle-earth, the majority pressed on. Not long after reaching Middle-earth, Fëanor was killed by Balrogs. The war he began, however, was to carry on through the entire First Age of the Sun.
Fëanor is remembered in fandom for being the person who started the Kinslaying, but primarily for being a selfish and obsessive person who was far too fond of his possessions. He stands as an example for all PPC Agents of how NOT to behave toward pretty baubles. Even—scratch that, especially—if they are really, really shiny. Some of Fëanor's followers eventually became PPC agents, such as various incarnations of Maglor, the last survivor of Fëanor's sons, and Nendil Morifëa.