The period of the Eastern Question which Mr Mosely treats is significant because it represents the opening stage of the nineteenth century phase of that problem. As pictured in historical literature, the diplomatic crisis of 1839 seemed to burst on Europe with complete unexpectedness, and the diplomatic revolution which followed in the relations between England, France, and Russia was not clearly motivated by the previous train of development. That gap in our knowledge has now been filled by a systematic and exhaustive use of the rich Tsarist archives in Moscow.