In June and early July 1920, during the offensive of the south-western front, battles between the Polish army and Semyon Budyonny's Soviet 1st Horse Army were fought at Kortec. On the Polish side the battles were fought by: 1st Legion Infantry Division of Colonel Juliusz Rommel, 3rd Legion Infantry Division of General Leon Berbecki and 6th Infantry Division of Colonel Ottokar Brzoza-Brzezina. The aim of the battles was to beat Semyon Budyonny's army at Kortse, but poor co-ordination of operations and a lack of communication between the divisions led to the fact that the Polish side's armed actions were limited to many minor clashes with the enemy's troops. In view of such a development of the situation on the front, the Polish side abandoned offensive actions in the area of Kortec.

The next battles near Kortec took place in September 1920 during the autumn offensive of the Polish army in Ukraine. The battles were fought by the 2nd Cavalry Division of Colonel Gustaw Orlicz-Dreszer with the Soviet 44th Rifle Division under the command of Commander Ivan Dubovoy. These battles ended with the partial success of the Polish troops, i.e. the recapture of the occupied areas, but the goal of destroying the headquarters of the 1st Cavalry Army and its units was not achieved.

Some of the Polish soldiers killed in these battles were buried in a mass grave next to St Anthony's Church. Before the Second World War, the site was neat and tidy. During the Soviet era, the monument on this grave was partially damaged. Its restoration took place around 2013.

A concrete tombstone in the form of an obelisk topped with an eagle was placed on the grave. On the base of the obelisk the inscription is engraved: "To Polish soldiers / fallen in defence of the Fatherland / near Korce in July 1920".