Massacre of Uman

Uman was a well-fortified town that held a large garrison part of Polish troops. This fact made Uman one of the primary targets of Koliyivschyna movement, and, probably, the siege of Uman was planned well in advance. Ivan Gonta, an officer in the private militia of Count Franciszek Salezy Potocki (composed of Registered Cossacks) was accused of connections with haidamakas by local Jewish community three months before the siege; however, due to the lack of hard evidence and the sudden death of a star witness on his road to Uman no formal charges were made. Although Ivan Gonta was de facto the commander of Uman cossacks he was not the most senior in their ranks.

In early June 1768 the Ukrainian rebels under the command of Maksym Zalizniak marched on Uman after capturing Cherkasy, Korsun and Kaniv. As Zalizniak openly encouraged the slaughter of Jews and Poles, the town was filled with refugees. A large camp filled with Polish nobility and their private militia, regular soldiers and Jewish refugees was stationed outside the city walls. Polish troops outnumbered the forces of rebels, and therefore it was decided that some of the forces should guard the ramparts while Gonta with his cossack unit would meet the Haidamakas in open battle. However, when Gonta met Zalizniak's units he openly declared that he is going to join Koliyivschyna. Some sources claim that the formal commanders of the unit were sent back to Uman, although the authenticity of the story is highly disputed.

The united troops razed the encampment on June 14 and tried to penetrate the ramparts by concealing the rebels behind the backs of Gonta's Registered Cossacks. However, the attempt failed, and so the siege started on June 17. The very first day large number of Ukrainians deserted the ranks of Polish forces and joined the rebels when the city was surrounded.

After three days of the siege the city fell to Zalizniak in spite of a courageous defense in which the Jews also played an active role. After the city was taken a violent and bloody massacre (where Mladanovitch was himself killed) took place. The Jews then gathered in the synagogues, where they were led by Leib Shargorodski and Moses Menaker in an attempt to defend themselves, but they were destroyed by cannon fire. Most of the remaining Jews in the city were subsequently killed. According to earlier estimates the number of Poles and Jews massacred was 20,000. The estimate given by Gonta for self-embellishment during his trial was 33,000. These numbers are considered exaggerated by the modern historyography, with numbers of Poles and Jews who were killed in the “massacre of Uman” estimated at ca. 2,000.