The question slumbered for a century and a half, and when it reappeared the Turk was again on the side of the light. In 1815, there was a dispute on this subject between Austria and Turkey. At that time the Jews of Turkey were treated better than the Jews of Austria. Austria applied to Turkish Jews visiting her territories the disabilities imposed upon her own Jews. Turkey protested on the ground that, according to the treaties--mainly the Treaty of Carlowitz--in force between the two powers, Austria had no right to make any distinction between Turkish Jews and other subjects of the Ottoman Porte. This contention was held to be valid by the Austrian Government, and the incident was terminated by the issue of an instruction to the police of Lower Austria, where the disabilities complained of were in force, ordering them to treat all Turkish subjects alike without distinction of race or creed. The Treaty of Carlowitz by which this case was governed left very little option to the Austrian Government,[66] inasmuch as the reciprocity for which it stipulated was not based, as in other treaties, on what is known as "National treatment," that is to say that the nationals of each contracting party visiting the territories of the other shall be treated on the same footing as the nationals of the territories they visit. The reason, no doubt, was that the racial and religious heterogeneity of both Empires, and the differential treatment to which it gave rise in their respective internal administrations, could not be recognised internationally without grave risk of friction and controversy. The lesson was not lost on other States, especially those which desired to maintain their differential treatment of Jews as against the doctrine of undenominational Nationality which was chiefly championed by France. The result was a strengthening of the "National treatment" clause of commercial treaties, and this, with the progress of religious liberty, led to a succession of fresh international disputes.