At the end of the summer and in the autumn of 1916, on the Macedonian Front in the part of Mount Nidze, there was a battle between Serb and French troops on one side and Bulgarian and German troops on the other. For months, the Allies had been thinking about the great offensive of the Macedonian Front to mobilize Romania and its entry into the Entente. According to data from the French army, the Central Powers in this region had 160 battalions (155 Bulgarian and 5 German), while the Entente had more than 200 battalions (72 Serbs, 60 British, 52 French, 12 Italian and 6 Russian). In the center of the Front overlooked the Kaimkchalan peak, with an altitude of 2,528 meters.
Although the first Allied intervention took place on 20 August 1916, with the bombardment of the Bulgarian positions and the occupation of some slopes in the eastern part of the mountain by the two Serbian divisions, the offensive began much later than planned. In early September, the mountain became an important battleground for battles between Bulgarian and Serbian troops. At the same time, a large proportion of the Allied troops were manoeuvring towards offensive positions. Finally, on 12 September, the Allies went on the offensive and succeeded without difficulty in taking some Bulgarian positions. The offensive continued uninterrupted in the following days, with the aim of not allowing Bulgarian troops to regroup.
On 17 September, French troops had reconquered Florina, previously occupied by the Bulgarian army. On the eve of 18 September, the Serbian army succeeded in conquering the Kaimkchalan peak and preventing Bulgarian counter-attacks. After these successes, on 20 September, the Allied army reached the second line of defence to which the Bulgarian troops had withdrawn. General Cordonnier, who commanded the offensive, decided to postpone the attack for a few days in order to receive supplies from the south and for the soldiers to rest. During this time the heavy artillery was brought in and, on the morning of 24 September, the strong pressure on the Bulgarian positions continued, although their resistance seemed unwavering. General Sarrail, stationed in Thessaloniki as commander-in-chief of the Allied army at the Macedonian Front, ordered a reinforced regrouping in preparation for the new offensive on the western part of the Front on 3 October. In difficult climatic conditions, the Serbian 1st and 3rd armies managed to cross the Black River, and the Bulgarian army began to withdraw. General Cordonnier, from his Florina base, then ordered to concentrate on increasing penetration to the north and pursuing the enemy. The strong resistance of the Bulgarian troops, installed in the dug relief, made its orders difficult to reach.
Overall, with 4000 dead or wounded and 17000 evacuated to hospitals, the October 1916 efforts did not yield any significant results for the Allies on the Macedonian Front. Significant, though slow, progress was made in the second half of November 1916. A small chapel and an ossuary of Serbian soldiers who died during the battle bear witness to the fierce fighting of the time. Every year, on September 18, the delegations of the armies who took part in this battle pay tribute to the fallen soldiers.