The issues of ownership, control and further fate of the Bosphorus and Dardanelles - the straits connecting the Black Sea with the Mediterranean - were one of the key issues in European geopolitics. The straits were the most important artery for trade and military navigation near the southern borders of the Russian Empire. R. Bobroff in his research turns to Russia's policy regarding the straits in the run-up to and during World War I and analyzes the agreements reached by S. D. Sazonov, not sharing the generally accepted opinion of them as a triumph of Russian diplomacy.