Ulmo is the Lord of Waters. He is alone. He dwells nowhere long, but moves as he will in all the deep waters about the Earth or under the Earth. He is next in might to Manwë, and before Valinor was made he was closest to him in friendship; but thereafter he went seldom to the councils of the Valar, unless great matters were in debate. For he kept all Arda in thought, and he has no need of any resting-place. Moreover he does not love to walk upon land, and will seldom clothe himself in a body after the manner of his peers. If the Children of Eru beheld him they were filled with a great dread; for the arising of the King of the Sea was terrible, as a mounting wave that strides to the land, with dark helm foam-crested and raiment of mail shimmering from silver down into shadows of green. The trumpets of Manwë are loud, but Ulmo’s voice is deep as the deeps of the ocean which he only has seen.
Nonetheless Ulmo loves both Elves and Men, and never abandoned them, not even when they lay under the wrath of the Valar. At times he win come unseen to the shores of Middle-earth, or pass far inland up firths of the sea, and there make music upon his great horns, the Ulumúri, that are wrought of white shell; and those to whom that music comes hear it ever after in their hearts, and longing for the sea never leaves them again. But mostly Ulmo speaks to those who dwell in Middle-earth with voices that are heard only as the music of water. For all seas, lakes, rivers, fountains and springs are in his government; so that the Elves say that the spirit of Ulmo runs in all the veins of the world. Thus news comes to Ulmo, even in the deeps, of all the needs and griefs of Arda, which otherwise would be hidden from Manwë.