pursuing his Phrygian Hectors over the dusty plains of Troy. He was mad, no doubt, to march so far over those weary deserts into Turkestan, through those dreadful defiles of the Hindu Khush. Only the mutiny of his army turned him back when he reached the farthest of the Five Rivers of the Punjaub. And then it was frantic lunacy to lead his army home along the burning coasts of the Persian Gulf. That experience taught him, it seems, a lesson which he might well have learnt earlier, namely, the value of sea-power for conquerors and empire-builders. When he died he was projecting a naval expedition along the coasts of Africa. The disaffection of Athens had deprived him of the fleet which ought to have belonged to a Panhellenic army, and Alexander had been forced to destroy the Persian fleet by a siege of its arsenal and headquarters, the island city of Tyre. Most conquerors have a touch of insanity, no doubt. The sanest of them is Julius Cæsar, and the