During the 1877-78 Russo-Turkish War, the Balkan (European) theatre of military operations proved to be decisive for the course of events due to both political and strategic reasons. The most important battles and engagements occurred on Bulgaria's territory with the direct assistance of the Bulgarians. The Russo-Turkish War brought about a real turning point in the art of warfare. It brought to the fore the significant role played by sappers' units and strategic encircling movements and did away with blind faith in the omnipotence of armored men-of-war and their bombardment, their place being taken by cutters and torpedo-boats. The use of shrapnel shells and quick-firing rifles likewise affected the development of military art. The infantry definitely won the title of "Queen of combat." The war underlined the importance of medical services and good communications in the rear of the army. It is erroneous to draw comparisons between the 1877-78 Russo-Turkish War and the 1870 Franco-Prussian War. Neither the terrain, the character of the adversary, nor the methods of waging the war had anything in common. The difficulties that the Russian army surmounted were far greater than those that faced the Prussian army. The insufficient preparation of the regular cavalry (dragoons, lancers and hussars) became apparent in the course of the war. The commanding officers of the detachments preferred to use Cossack cavalrymen who were better able to cope with reconnaissance activities and with military operations. The main shortcoming in the training of the artillery was insufficient coordination between its operations and those of the infantry. The very fate of the campaign depended on the success of the particularly complicated and bold plan to cross the Balkan Mountain Range under winter conditions.