AMONGST THE NUMEROUS NOMAD RACES of Central Asia there were two great tribes - the Mongols and the Turks - who in the thirteenth century overran a great part of the Muslim empire and penetrated beyond it. Hulagu Khan captured Baghdad, the seat of the renowned Abbasid Khalifate and the Mongols soon overran the Syrian empire of Saladin, which had come now under the rule of the Mamluk Sultans of Egypt. The Mongols on different occasions made several ineffectual attempts to invade Egypt, and were repulsed by the bravery of the Mamluks; but they entered Europe and advanced as far as Hungary. They were nomads and, as a rule, could not settle down; so after ravaging a country they usually retired from it. For a time, however, they retained possessions in China, and, as the Golden Horde, ruled in the Crimea; but they left no permanent mark on the Muslim empire of the Khalifate; and so we may pass them by. It so happened that one day Ertoghul was proceeding with a small band of men in the direction of Anatolia, where he unexpectedly came upon a battlefield (Angora) in which the Seljuk Sultan was contending against a strong and determined foe. At once Ertoghul and his four hundred men joined in the conflict and helped to gain a victory for the Seljuks. On another occasion also they rendered valuable military assistance. The Sultan in return for this welcome aid allowed them to settle on land where good pasturage and suitable winter quarters were found. This was in the neighborhood of Angora and not far from the boundaries of the Byzantine province of Bithynia...