These primitive conquerors had several great advantages over their more civilized neighbors. One was their extraordinary physical stamina. The weeding out of the weak began practically at birth. Children, weaned from mother’s milk, were fed on mare’s milk for a few years and then were left to care for themselves as best they could. As clans gathered around the open fires, where all the food was cooked in huge pots, the strongest men ate first; the aged and women next; and the children were left to fight over the bones and scraps. Food was abundant in the spring when mutton, game and fish were available. In the early winter the hordes lived largely on millet, and fermented mare’s milk. The latter had a high alcoholic content and was quite “heady” for the younger children. By the end of the winter, the clansmen were reduced to foraging and making raids on the herds of other tribes. The old and weak were left to perish. Only the hardiest survived. Another great advantage of the militant nomads over their victims was their ability to ride the horse. Everywhere else in the ancient world, this animal was used only to draw the heavy war chariots. The Mongols, fearing nothing, mastered the horse and became expert cavalrymen. The resulting mobility was a tremendous asset in warfare. Without the horse, the Mongols would never have been able to conquer such vast territories. Learning to ride as children of three or four, they were superb horsemen in their early manhood and hunted with consummate skill. When they appeared upon the horizon in a cloud of dust and with a clatter of hooves, it was only a matter of minutes before each dropped down like an eagle upon his prey. Of even more strategic importance was their conception of the fifth column. Poor always, in comparison with their neighbors, whose lands and goods they coveted, they—like their Russian descendants—developed a technique of boring from within. Ahead of them were sent humble-looking barterers or beggars, who easily bribed and cajoled their way inside the walls of a city. At the critical moment, the unfortunate citizens would find their gates open and hordes of wild tribesmen bursting in upon them with bloodcurdling yells. Whether at home or in the field, these nomads lived in yurts, or domelike tents, made of felt and mounted on wooden carts, drawn by oxen. They spent most of their days on horseback, hunting, fishing and constantly fighting among themselves and with neighboring clans. Often they remained in the saddle for days, eating little or no food. Between each major conquest, there were long periods when fighting was confined to the steppe lands. It was only when an outstanding genius appeared that they attempted the invasion of the more civilized countries—Europe, China or the Near East—which, throughout the ages, were constantly on the defensive against them.