Then, while the fight was still raging, Concobar called to him his son Ficra, and said to him:--"Thou and Illan the Fair were born on the same night: and as he has his father's arms, so thou take mine, namely, my shield which is called the Ocean, and my two spears which are called Dart and Slaughter, and my great sword, the Blue-green blade. And bear thyself manfully against him, and vanquish him, else none of my troops will survive." Ficra did so and went against Illan the Fair; and they made a stout, warlike, red-wounding attack on each other, while the others looked on anxious: but none dared to interfere. And it came to pass that Illan prevailed, so that Ficra was fain to shelter himself behind his father's shield the Ocean, and he was like to be slain. Whereupon the shield moaned, and the Three Waves of Erin uttered their hollow melancholy roar.[77-2] [77-2] The "Three _Tonns_ or Waves of Erin" were the Wave of Tuath outside the mouth of the river Bann, off the coast of Derry; the Wave of Rury in Dundrum Bay, off the county Down; and the Wave of Cleena in Glandore Harbour in the south of Cork. In stormy weather, when the wind blows from certain directions, the sea at those places, as it tumbles over the sandbanks, or among the caves and fissures of the rocks, utters a loud and solemn roar, which in old times was believed to forebode the death of some king. The legends also tell that the shield belonging to a king moaned when the person who wore it in battle--whether the king himself or a member of his family--was in danger of death: the moan was heard all over Ireland; and the "Three Waves of Erin" roared in response. See "Irish Names of Places," Vol. II., Chap. XVI. The hero Conall Carnagh, sitting in his dun afar off, heard the moan of the shield and the roar of the Wave of Tuath: and springing up from where he sat, he said: "Verily, the king is in danger: I will go to his rescue." He ran with the swiftness of the wind, and arrived on the Green of Emain where the two young heroes were fighting. Thinking it was Concobar that crouched beneath the shield, he attacked Illan, not knowing him, and wounded him even unto death. And Illan looking up said, "Is it thou, Conall! Alas, dreadful is the deed thou hast done, not knowing me, and not knowing that I am fighting in defence of the Sons of Usna who are now in deadly peril from the treachery of Concobar." And Conall, finding he had unwittingly wounded his dear young friend Illan, turned in his grief and rage on the other, and swept off his head. And he stalked fierce and silent out of the battlefield.