In attempting to understand this motley field, two principles of the empire must always be kept in mind. One is the Mohammedan principle, which allows non-idolatrous peoples to retain their religion on payment of a poll-tax, at the same time freeing them from military duty. The other is the Turkish principle, which allows different nationalities to remain distinct, but requires them to be represented before the sultan by a political or religious head. There is no assimilating power tending to unify these many races and religions, like that of the British, or even the Mughals, in India. The consequence is that all these separate units form a conglomerate state, binding religions and nationalities together in a repellent contact ready to fly apart into fragments the moment the external fettering bond snaps. —EDWARD A. LAWRENCE in “Modern Missions in the East.” When the Turks laid siege to Vienna in 1529 it was the period of their greatest prosperity. If at that time the entire Ottoman empire had been enclosed by a modest wall it would have taken a large army of workmen from that day to the present to tear down the old boundaries and reerect them upon the new lines. A most interesting feature of this constant change is that it has been almost uniformly a decrease in the area of the empire. At that time it was the most powerful realm in the world. It included all the states bordering upon the Mediterranean except Spain, France, Italy, and Morocco, the entire Black Sea coast, and nearly all that of the Red Sea, as well as the lower Danube district. Gradually province after province and state after state have slipped from the grasp of the sultan. The decline became decided in 1606 beginning with the treaties of the Sitavorok. With the treaty of Carlowitz in 1699 it amounted to actual dismemberment. The epithet, “The sick man of the East,” was applied to the sultan, after this loss of prestige from which he never recovered. The retrograde movement continued through the seventeenth century. While the Ottoman empire had been the object of extreme fear upon the part of the nations of Europe up to the beginning of that century, each of them vying with the rest in seeking the favor and good-will of the reigning sultan, at the beginning of the eighteenth century Turkey had reached a point where it was protected by its relative weakness. It no longer inspired fear in the hearts of European rulers, while its impotency and the mutual antagonism of its subject non-Moslem races rendered aggressive national action practically impossible. Parts of its territory became wholly lost, like the Danube provinces, the Caucasus and Tunis, while other sections became semi-independent like Bulgaria, Cyprus, Crete, and Egypt.