In the Polish-Ukrainian War of 1919. Brzeżany was defended by the battalion of Lt. Col. Bolesław Dunin-Wąsowicz, belonging to the 9th Infantry Regiment of the Legions. After four days of fierce fighting, the defenders had to give way under heavy enemy artillery fire. Among those killed in the fighting was Bolesław Dunin-Wąsowicz (posthumously appointed captain and awarded the Order of Virtuti Militari V Class and the Cross of Independence). He was buried in an unnamed grave on Lysoni Hill in Brzeżany. Other Polish soldiers killed in these battles are buried in the so-called Polish cemetery, where a large military quarter with a main monument has been arranged. No documents have survived to prove how many soldiers were buried in this quarter. At present, only 4 graves have preserved name plates, including that of Leon Kozłowski.

The plot has the shape of a rectangular field with an area of several dozen square metres. It is surrounded by a 1 m high wall of stone blocks, covered by a concrete eave. There are 4 steps leading up to the interior of the quarters, the level of which is much higher than the surrounding area. A monument stands in the central section. Its composition consists of simple, cubic forms. There is a high slab in the centre, its sides bounded by lower cuboid blocks of varying heights. On the smallest, outermost ones, concrete flower vessels were placed. The vertical arrangement of the monument is closed on the front side by a large reclining slab, which is the base for the other elements. The whole is made of concrete, coloured bright red. The inscription on the front wall reads: "TO THE HEROES / OF THE STRUGGLE / FOR POLAND / 1918-1920". On the back wall of the monument was engraved the following inscription, now defunct: "FOR THE HONOUR OF BELONGING TO / OUR SOLDIER'S CIRCLE / ABUNDANTLY PAID IN BLOOD. / HONOUR AND GLORY TO THEM ALL, / AND LET THE MEMORY OF THEM ALWAYS / BE CLOSE TO OUR HEARTS. / BRZEZANY 1932".

In 1945-1946, after the expulsion of Poles from Brzeżany, Komsomol activists were employed on orders from the NKVD to liquidate the inscriptions on the monument and graves. Brzeżany residents who painted over traces of ripped letters with oil paint were punished with fines and an order to leave the city within 24 hours.

In recent years, volunteers from Poland have carried out cleaning work at the cemetery as part of the campaign "Mogila pradziada ocal od zapomnienia". The patron of this action is TV Wrocław - Studio Wschód.