Oromë is a major protagonist in The Silmarillion.
He is the brother of Nessa and husband of Vána, also known as Araw in Sindarin, Aldaron ("Lord of the Trees"), Arum, Béma,Arāmē, The Huntsman of the Valar, and The Great Rider. During the Years of the Trees, after most of the Valar had withdrawn completely from Middle-earth and hidden themselves in Aman, Oromë still hunted in the forests of Middle-earth on occasion. Thus, he was responsible for first finding the Elves at Cuiviénen.
Being a powerful huntsman, Oromë [ˈorome] was active in the struggles against Morgoth, and was renowned for his anger, being the most terrible of the Valar in his wrath. He has a great horn called Valaróma and a great steed called Nahar. In "The Book of Lost Tales", there is the sentence "There sang Amillo joyously to his playing, Amillo who is named Omar, whose voice is the best of all voices, who knoweth all songs in all speeches; but whiles if he sang not to his brothers harp then would he be trilling in the gardens of Oromë when after a time Nielíqui, little maiden, danced about its woods." It is mentioned in the Appendix on Names that Nielíqui is the daughter of Oromë and Vána.
In The Return of the King, Théoden is compared to Oromë when he leads the charge of Rohirrim in The Battle of the Pelennor Fields: "Fey he seemed, or the battle-fury of his fathers ran like new fire in his veins, and he was borne up on Snowmane like a god of old, even as Oromë the Great in the battle of the Valar when the world was young."
Thorin and Company