In the beginning there was only one: Eru. But he grew lonely, and so created the music of Ainur. So beautiful was this music that from it came the Valar, and they too contributed to the music and began forming the world.
One however, tried to change the music and created discord from which came many evils. This was Melkor and he strove to create a different world to the one in Eru's vision and so alienated himself from his brothers.
Following the completion of Ea, the world that is, the first race, the Ainur, beings of pure spirit came into the Timeless hall , and these were called the Valar. They were fourteen in number and they wanted to create a beautiful world like in the vision.
They built two great lamps in the north and south of Middle Earth, and many beautiful gardens and forests, however Melkor, the most powerful of them, destroyed it all. So with much sorrow the rest of the Valar moved west to Valinor, which would later be known as the Undying Lands. Melkor remained into Middle Earth and began to build great fortresses and Castles and dug the Great Pit Of Utumno.
In Valinor the Valar created the Vision, and it was beautiful, and two enormous trees lit the continent, and so began the age of the trees. It was during this age that the second race came into Arda, and into being and these were the Maia. They were far greater in number, although far lesser in power than the Valar. Melkor came to Valinor, with his maiar and cast down the trees of light and made war 5 times on the Valar.
Story Arc: War of Wrath
During this was Melkor summoned all of his evil creatures and assembled them and prepared to wage war and destroy Valinor. The Valar and Maia and elves fell upon him and his army with such wrath that had never been seen.
His armies were decimated. His fortresses destroyed, and he was beheaded and cast into the Void. Sauron-his lieutenant was the only survivng General of his after that war.
Lords of Valar
King Of All Valinor and Arda. He resides upon the tallest mountain in existence. And his powers lie in the air and the wind and the thunder.
All the birds are his symbols, and none more so than his Great Eagles. Speech is his also hence why he loves poetry and music. His wrath is terrible, and scared even Melkor. He is the most powerful of the Aratar.
It is commonly believed that Gwahir is a descendant of one of his great eagles who he had sent as spies to spy upon Morgoth. Manwe is second most attune to the will of Eru. He is prophesised to slay Melkor at the final battle.
The smith. He forged the two lamps that lit the world, and all the mountains and mines and caves and cliffs are his work. His blow is earth shaking, his power fantastic and his creations are incredible.
He forged the weapons of the Valar during the War of Wrath and has power over all land. Dwarves above all worship him. He created the dwwarves from clay before even the elves were made, but Eru only gave them conciousness after the firstborn (the elves) had been born. It is interesting to note that the only Maiar known to have fallen to evil are his.
He is the master of the hunt and tamer of beasts. He is loved by all horsemen. His steed is the great Nahar, who shakes the very continent with his hoofbeats.
When Orome blows his great hunting horn, all enemies flee, for it is the signnal of their doom. He sent forth 2 of the Istari to Middle Earth. It was Orome who found the elves in their woods and protected them from melkor. He loves them greatly and was the last and most sad of the valar to leave middle earth.
He is the master of all waters, and the Ocean is his domain. He is well loved by all sea farers and feared by all dwarves and orcs. His is the wave that breaks ships. All the beasts of the Ocean are his and his great voice booms too deep for mortal ears.
He is the most powerful of the Valar after Manwe. He controls every water source throughout arda and none dare to disturb him. He has no fixed domain and rarely comes out from the sea save to aid champions of his or to meet with the Valar.
Deep within the halls of Aule resides Mandos, and it is here is Mansion Mandos stands. He is the speaker of Doom and is most in tune to the will of Eru.
He is unmoved by pity for he is the Lord of the Dead and knows the fates of all from the song of Eru. He is named Mandos after his mansion and it is here that elves believe they go after death.
Queens of the Valar
Queen of all Arda and spouse of Manwe, she is the creator of Stars and light. She is the most beautiful of all the Valar for the light of Eru shines upon her and in her eyes. She is much loved by all those who arose after the kindling of the stars and none more so than the elves. She took drops from the great trees and used them to paint stars.
The weeper. She represents the grief and sorrow which leads to wisdom. She lives in the farthest corner of Valinor, and it was through her tears that the Great Trees were brought about. She weeps not through sorrow but in remorse for the many atroticites that have been comitted.
The nourisher. She provides nourishment to all those on middle Earth. After the poisoning of all her creations in Middle Earth she feared that the trees would fall, following her husband's construction of the dwarves and so pleaded with Eru to allow her to protect some of her creations from Melkor and the other races, and so he allowed her to create Ents.
These 8 are the Aratar, the more powerful Valar, excluding Melkor. The other Valar are named:
Lorien: Master of Dreams and Desires
Tulkas: The Wrestler, he is the strongest of all the Valar.
Vána: Creater of plants and flowers and birdsong.
Nessa: The Dancer, all woodland creatures come to her.
Vairë: The Weaver and wife of Mandos.
The most powerful of all the Valar and Master of Darkness and Evil. He is known for creating the first trolls, orcs, and other dark creatures known for being pollutions of various other races.
Melkor's power has greatl diminished over the years due to the fact that he has expended vast amounts in the creation of his armies.