§ Of the Rings of Power and the Third Age The Silmarillion

In that last battle were Mithrandir, and the sons of Elrond, and the King of Rohan, and lords of Gondor, and the Heir of Isildur with the Dúnedain of the North. There at the last they looked upon death and defeat, and all their valour was in vain; for Sauron was too strong. Yet in that hour was put to the proof that which Mithrandir had spoken, and help came from the hands of the weak when the Wise faltered. For, as many songs have since sung, it was the Periannath, the Little People, dwellers in hillsides and meadows, that brought them deliverance.