The principle of the personality of law and religion came most visibly into play in the heart of the empire. Prevalent in the Orient from the time of Assyria’s greatness to the present day, it is not easily to be understood in a land that has wholly separated religion and law. Where these two ideas are united, two men who hold different faiths must perforce live under different laws.[65] Islam inherited the idea of the personality of law through the Sassanian Persians, and endeavored to apply it with simplicity by drawing a single line between Moslem citizens (_Muslim_) and non-Moslem subjects (_Zimmi_).[66] The Ottomans adopted the idea unreservedly and worked it out into a complicated system: each considerable body of their non-Moslem subjects, Greek Orthodox, United Greek, Armenian, and Jewish, they left, in time, not merely to its own religion, but to its own law and the administration of its law in all matters that did not concern Moslems.[67] Proceeding yet farther with the same principle, they granted even greater privileges to foreigners who wished to reside within the empire. Except for a tax upon the land which they might occupy, for the necessity of paying customs duties, and for responsibility to Ottoman courts of justice in civil cases in which Ottoman subjects were concerned, such foreigners were almost wholly free from Ottoman control, freer far to do as they pleased than they could be in their native lands. Regions existed where nearly all the inhabitants obeyed one law. In Bulgaria and Greece few were not Greek Orthodox. In the interior of Asia Minor few were not, at least legally, Mohammedan. But in the great cities of the empire, and especially in the capital, there was an immense variety of obedience. Not only did the various colonies of foreigners and the various subject nationalities have their separate rights under different systems, but individuals among them, such as ambassadors and clergymen, had special privileges and immunities. Even among the Mohammedans there were various distinctions. Several large classes were privileged, and in different ways, including all the people of court and church, of the army and the law, of government and education. The social and legal structure was thus scarcely less complicated than that of medieval Western Europe, with its interlocking of feudal and official and royal privilege, of clergy and nobility, of free and chartered cities. INSTITUTIONS OF GOVERNMENT