"The Enemy and the Valar had warred twice before. After the first war, the Valar built Valinor, which is their paradise and carefully guarded. The Enemy roamed this land freely, doing as he pleased. There were Elves. We all lived around a great lake far east of here. The Enemy came, picked us off, took us back to torture and forcibly breed and torture the children and use his magic to create orcs. The Valar knew none of this; they didn't even realize Elves existed. When they learned of it they went to war with the Enemy again. The war lasted centuries. Continents crumbled. The Valar won, and took the Enemy prisoner. His creations still roamed freely, and the land was hazardous, and they offered to take us to Valinor and restore our lost loved ones to life.
Some of us accepted.
Three Ages later the Enemy petitioned for pardon. He threw himself at Manwë's feet and spoke very convincingly and pleaded for the chance to become the smallest, humblest creature in Valinor and right the wrongs he'd done.
Instead, he started tearing our people apart.
The King, my grandfather, had remarried, and a consequence of the remarriage was that his first wife, who died, was not allowed to return to the world. The King's son by his first wife resented this and resented the remarriage and resented his half-siblings. They got on civillly, but did not love each other as brothers, and the Enemy spread rumors that each of them were seeking to destroy the other and have him ousted from the family, and after a few centuries of these rumors they started to gain traction."