In the mean time, the surface of the sea, far and wide in every direction, was covered with the wrecks, and remnants, and fragments strewed over it by the battle. Dismantled hulks, masses of entangled spars and rigging, broken oars, weapons of every description, and the swollen and ghastly bodies of the dead, floated on the rolling swell of the sea wherever the winds or the currents carried them. At length many of these mournful memorials of the strife found their way across the whole breadth of the Mediterranean, and were driven up upon the beach on the coast of Africa, at a barbarous country called Colias. The savages dragged the fragments up out of the sand to use as fuel for their fires, pleased with their unexpected acquisitions, but wholly ignorant, of course, of the nature of the dreadful tragedy to which their coming was due. The circumstance, however, explained to the Greeks an ancient prophecy which had been uttered long before in Athens, and which the interpreters of such mysteries had never been able to understand. The prophecy was this: The Colian dames on Afric's shores Shall roast their food with Persian oars. CHAPTER XII. THE RETURN OF XERXES TO PERSIA. B.C. 480 Mardonius.--His apprehensions after the battle.--Depression of Xerxes.--Mardonius's address to him.--Mardonius offers to complete the conquest of Greece.--Effect of Mardonius's address.--Xerxes consults Artemisia.--Artemisia hesitates.--Her advice to Xerxes.--Xerxes adopts Artemesia's advice.--His anxiety increases.--Xerxes commences his retreat.--He sends his family to Ephesus.--Excitement in the Greek fleet.--The Persians pursued.--Debate among the generals.--Themistocles outvoted.--Another stratagem of Themistocles.--His message to Xerxes.--Duplicity of Themistocles.--Retreat of Xerxes.--Horrors of the retreat.--Sufferings from hunger.--Famine and disease.--Xerxes crosses the Hellespont.--Fate of Mardonius.--Xerxes arrives at Susa.--Xerxes's dissolute life.--His three sons.--Artabanus, captain of the guard.--He assassinates Xerxes.--Artaxerxes kills his brother.--He succeeds to the throne.