War of Wrath
The Eagles fought alongside the army of the Valar, Elves, and Men during the War of Wrath at the end of the First Age, when Morgoth was overthrown. In "The Silmarillion" it is recounted that after the appearance of winged dragons, "all the great birds of heaven" gathered under the leadership of Thorondor to Eärendil, and destroyed the majority of the dragons in an aerial battle.