Mineyko took part in the Greco-Turkish war of 1897. During the First Balkan War, in 1913, his strategic plans became crucial in achieving the decisive Greek victory at the battle of Bizani, which led to the capture of Ioannina and Epirus by Greece. As an engineer and head of the cartographic service of the Greek General Staff, and with his prior knowledge of the region, he prepared a plan for the outflanking movement which led to the taking of the strongly fortified Turkish position of "Bizani", which sealed entry to the Ioannina Valley. In November 1919, the affair became famous when, during the trial of General Staff Officers, the Athenian journals "Patris" and "Nea Ellas" revealed Mineyko’s contribution. For this achievement, he then received the Golden Cross of the Redeemer.