The Battle of Corellion and Gruumsh

A fight, started by the Celest Gruumsh, that led to the creation of the Seldarine from the Blood of Corellion another Celest, and the Oriki from the cut flesh of Gruumsh. This battle was the first combat between the Celestials, and it was gruesome fight. In the end, Gruumsh lost an eye, and the other Celests intervened, to prevent the two from ripping creation apart.

The Conflict began as most of the other Divine accepted Corellion mutability and passionate behavior, but these traits infuriated Gruumsh. When Corellion's flighty wonderings brought them close to Gruumsh, Gruumsh stuck out, and began a conflict that nearly ripped the Celestial planes apart.
  Much about this event is disagreed upon, but what is known is this is what started the two races, the Seldarine, the precursors to the Elves and Drow, and the Oriki, the origin of Ogres and Orcs. The Orcs claim that Gruumsh took his own eye after the combat in frustration of being unable to finish the fight, while the Elves claim that Corellion took his eye, and the rage of Gruumsh was what inspired to Celests to intervene.
  It was the Celests that intervened to end the fight, but the first blood of the divine had been done, and these new races of beings were formed. The Seldarine followed behind Corellion, and lived in their shadow.
  The Oriki would build strongholds around Gruumsh, who treated them like unwanted children. The Decedents of Oriki were not Oriki, but rather born with shortened life spans, and for many generations devolved into what we call Orcs today. Sometimes a Oriki is born, and is often worshiped by Orcs and seen as a sign from Gruumsh.
  Eventually Corellion found the Seldarine delightful, and spent some time with them in the Realm of Arvandor in the plane of Arborea. While enjoying the company of these beings, Corellon came to appreciate their ideas, and singled out those of great repute for special treatment.
  Corellion gave each of these luminaries a name; Aerdrie, Keptolo, Solonor, Naralis, Erevan, Hanali, Tarsellis, Rillifane, Zandilar, Labelas, and many more. These beings were treated as though Gods by the others.
  One of these beings, although privileged to be elevated above the rest, was not satisfied with being one of Corellion's. trusted underlings. She saw in the multiverse potential to make an impact beyond Corellion's flighty will. The entity who called herself Lolth spoke to the other luminaries, and wove an enticing tale of how they could attain superiority if only they could relinquish a bit of their individual freedom.
  Through this, she convinced them to relinquish every changing forms, and become a static image, turning away from the example of Corellion's wild, ever shifting ways. As this concept spread among the other Seldarine, the race of Elves was born.