The lesser of the Ainur were a host known as the Maiar, and while in Arda, they were the servants of the Valar. However, before the creation of the world, they took part in the Music of the Ainur, along with the Valar.

Though the Maiar were numerous within the Undying Lands, only a few were named in the histories of Men, for their concerns were seldom with mortal men and mortal lands, but rather with the Valar in the Blessed Realm.

Chief among the Maiar were Ilmarë, the handmaiden of Varda, and Eönwë, the herald of Manwë. But best known to the Children of Ilúvatur were Ossë and Uinen.