Two campaigns. The struggle for East Prussia in August-October 1914

The East Prussian operation of 1914 was the first armed clash of Germany and Russia at the East European Military Theater for the first time after the Seven Years of the War of 1756-1763. Moreover, that there were no insoluble and sharp contradictions between them.
The terrorist act in Sarajevo June 15/28, 1914 promoted the spring of the interethnic crisis in the Balkans and involved the world into his orbit. Russia was supposed to only distract the troops of the opponents, according to its allies.
The East Prussian operation in August 1914 and subsequent battles on the eastern border of Germany until the beginning of November 1914 (when the region became an auxiliary direction) were of exceptional importance for the subsequent course of the struggle at the East European Military Theater. The author tried to find answers to unresolved or discussion issues related to the operation, its results and development