Byzantium has become a very potent element in the Osmanlis' character, more potent than the habits of the march or the instinct of the steppes. It has dictated their system of administration, dominated their outlook on life, penetrated their blood. But the heritage of "Rûm" is not the final factor in the Ottoman Empire as it exists to-day; for after the successors of Osman had founded their military monarchy with blood and iron on the ruins of one-third of Europe, they turned eastwards, with a genuinely Oriental gesture, and overran kingdoms and lands with the apparently mechanical impetus of all Asiatic conquerors, from Sargon of Akkad and Cyrus the Persian to Jenghis Khan and Timur. The stoutest opponent of the Osmanlis in Asia was the Anatolian Sultanate of Karaman--Moslem, Turkish, and the legitimate heir of those Seljuk Turkish Sultans who had given Osman's father his first footing in the land. Osmanli and Karamanli fought on equal terms, but when Karaman was overthrown there was no power left in Asia that could stop the Osmanlis' advance. The Egyptians and Persians had no more chance against Ottoman discipline and artillery than the last Darius had against the Macedonians. A campaign or two brought Sultan Selim the First from the Taurus to Cairo; a few more campaigns at intervals during the sixteenth and seventeenth centuries, when Ottoman armies could be spared from Europe, drove the Persians successively out of Armenia and Mosul and Bagdad. And thus, by accident, as it were, in the pursuit of more coveted things, the Osmanlis acquired "Turkey-in-Asia," which is all that remains to them now and all that concerns us here. "Turkey-in-Asia" is a transitory phenomenon, a sort of chrysalis which enshrouded the countries of Western Asia because they were exhausted and needed torpor as a preliminary to recuperation. Many calamities had fallen upon them during the five centuries before the chrysalis formed. The break-up of the Arab Caliphate of Bagdad had led to an interminable, meaningless conflict among a host of petty Moslem States; the wearing struggle between Islam and Christendom had been intensified by the Crusades; and waves of nomadic invaders, each more destructive and more irresistible than the last, had swept over Moslem Asia out of the steppes and deserts of the north-east. The most terrible were the Mongols, who sacked Bagdad in 1258, and gave the _coup de grâce_ to the civilisation of Mesopotamia. And then, when the native productiveness of the Near East was ruined, the transit trade between Europe and the Indies, which had belonged to it from the earliest times and had been the second source of its prosperity, was taken from it by the western seafarers who discovered the ocean routes. The pall of Ottoman dominion only descended when life was extinct.