The subject has been touched by many writers. There is perhaps no need to consider here the uses and gradual disappearance of the war-chariot. For present purposes it is sufficient to note that long before the historical age the armed hosts of the great Eastern Empires were composed in part of mounted men, who marched, and often fought, on horseback. The chariots and the people attached to them may have been the first “Cavalry”; but the word as used in this book refers to mounted men only--riders,--and riders who did some part at least of their fighting from the backs of horses. If the use of mounted men in war began in the East, to which Western nations owe so much, including even their religion, it soon extended to Europe. In the first conflict between East and West on a large scale of which we have any real knowledge, nearly five hundred years before Christ, the Persian invaders of Greece found that the Greeks had little Cavalry to oppose to the thousands of horsemen whom they brought with them. The men of Athens and Sparta fought on foot at Marathon and Thermopylæ. Even at Mount Cithæron, where Masistius in his golden cuirass charged and died, the Greek army was an army of footmen. Nevertheless there were some horsemen in Greece even then, especially on the plains of Thessaly; and the frieze of the Parthenon, of not much later date, shows helmeted Greek soldiers riding spirited horses. The horses are small, apparently not more than thirteen or at most fourteen hands, and are ridden barebacked, but they are evidently war horses. Then we have Xenophon’s well-known treatise on Cavalry, a thoroughly practical work, which must have been written in the first half of the next century; and after that the organisation of the Greek Cavalry is fairly well known. It was Alexander the Great who first showed what horsemen could do in war if properly trained and led. Until his time Cavalry seem to have fought mostly in loose swarms, rather as skirmishers and bowmen than as solid squadrons using the weight of the horse itself to overthrow and destroy bodies of footmen. He saw the value of “shock tactics,” and taught his Cavalry to use them, so that when he invaded Persia in 334 B.C. the famous horsemen of Persia went down again and again before his fiery onsets. They had themselves, according to Herodotus, some notion of charging in squadron on the battlefield, but they had never seen Cavalry used in mass, and neither they nor the Persian foot could stand against it. In the impetuous rapidity of all his movements, especially perhaps in the closeness and vigour of his pursuits, Alexander was in fact a model leader of horse, and his conquests were largely due to his Cavalry, which he not only wielded with dash and power against the Cavalry of the enemy, but kept thoroughly in hand even after a successful charge, and threw into the scale wherever they might be most required to help his foot soldiers.