 Later the forces of Gondor, led by Aragorn under an alias, attacked Umbar and destroyed the Corsair fleet, allowing Denethor II to devote his attention to Mordor.Denethor sent his son Boromir to Rivendell for advice as war loomed.There, Boromir attended the Council of Elrond, saw the One Ring, and suggested it be used as a weapon to save Gondor.