The mobilization for the Russian army ordered in July 1914 in the Kingdom of Poland and the “Manifesto to the Poles” proclaimed almost simultaneously by the Commander-in-Chief evoked several diverse (opposing) reactions. However, these divisions did not run, as one might expect for historical reasons, between different ethnic groups or social strata. Significant differences in the approach to the Commander-in-Chief’s “Manifesto” and the mobilization conducted in the Kingdom of Poland at the turn of 1914/1915 were revealed within each social stratum. Opposing attitudes were observed not only among the Polish political and social elite or military circles, but even among the general public. These divisions among the Poles were comparable to the reactions to the “Manifesto” and mobilization observed among the representatives of Russia’s political, military, and social elite. Mobilization in the neighboring partitions (for example, the Prussian partition) did not generate such divisions within each social stratum on the Polish and German sides. What took place at the turn of 1914/1915 within the framework of military activation of the Kingdom of Poland’s society was incomparable either in the case of other nations of the Russian Empire or elsewhere in Europe (apart from autonomous Galicia). This situation also came as a great surprise to Russia’s Western allies and caused great concern in Berlin and Vienna.