In the autumn of 1919, the Army of the Ukrainian People’s Republic (aka Ukrainian People’s Army), forced to fight along two fronts, yielded to the overpowering forces of Bolsheviks and the White Russian Army of General Anton Denikin. If that were not enough, it was decimated by the outbreak of typhus. Early in December 1919 the army and the authorities of the Ukrainian People’s Republic (UPR) found themselves in the “triangle of death” near Lyubar in Volhynia, with no further option for retreat. With Bolsheviks in the north, the White Army in the east and south, and Poles in the west, a decision was reached to have the still battleworthy troops go for the “winter campaign”, that is a guerrilla raid at the rear of Denikin and Bolsheviks, under the command of General Mykhailo Omelianovych-Pavlenko. The soldiers incapacitated by illnesses and wounds were disarmed by Poles and taken to the internment camp in Łańcut, where they were treated as “volunteer corps of foreign citizenship”. In turn, invited by the Polish Chief of State Józef Piłsudski, the Chief Otaman of the Ukrainian People’s Army Symon Petliura, left for Warsaw on 5 December 1919.

As envisaged in the Polish–Ukrainian agreement signed in Warsaw on the night of 21/22 April 1920, and the accompanying military convention, the Polish and Ukrainian armies started their joint fight against the Bolsheviks. The purpose of the “Kyiv raid” was to liberate central Ukraine from under the Bolshevik occupation and to crush the forces of the Red Army stationed there. Two Ukrainian units were established before the start of the offensive: 6th Sich (Ukrainian) Infantry Division under the command of Colonel Marko Bezruchko, and the 2nd Infantry Division under Colonel Oleksandr Udovychenko. By the end of April 1920 the two divisions had only mustered 556 officers, 3348 soldiers, 11 cannons, and 65 machine guns altogether. Their presence at the side of the attacking Polish army of 60,000 was of mostly propagandist importance.

The heroic First Winter Campaign of General Pavlenko behind the enemy lines ended on 6 May 1920, when his troops broke through the line of the front near Yampil on the Dniester. The march lasted for five months and had the Army of the Ukrainian People’s Republic march over 2500 km behind the lines of the “White” and “Red” armies. Having concluded that guerrilla raid, the force was in a miserable state with just 479 officers and 3840 rank-and-file soldiers equipped with 12 cannons and 81 machine guns. That meant that the Ukrainian army required a breather, reorganisation, and new drafts and provision of weapons and ammunition even more than that.

The time that was always short

On 7 May Poles captured Kyiv, deserted by Bolsheviks. Two days later a joint Polish–Ukrainian military parade with Colonel Bezruchko’s 6th Sich Division was held in the capital of Ukraine. Yet the liberation of Kyiv only marked the midway to the success. Now the main task was to have the UPR Army expanded so that it could assume the duty of defending their homeland, while the detachments of the Polish Army were to be transported to Belarus for the decisive clash against the Red Army.

Here, Piłsudski counted on exploiting the fairly strong anti-Bolshevik guerrillas supporting Petliura. This is what he wrote in a letter to Prime Minister Leopold Skulski:

I am being told by all and sundry about various detachments being and having developed ahead of our front. They attack the withdrawing Bolsheviks, and break them apart in seesaw fighting, in which both sides gain ground. Some such troops consist of 5,000 or 6,000 men at arms. Some of those report to our commanders, asking for orders, guidelines and possible aid.

Those insurgent troops were however reluctant to join a regular army, and were loath to obey discipline. As a rule, they were active within their home county, and never left its borders. Although many otamans cooperated with the authorities of the UPR, the peasants they commanded as a rule were only driven by the eagerness to take revenge on the local Bolshevik administration.

In such circumstances, the only way of expanding the Ukrainian army was to conduct a national mobilisation. However, the indecision of the UPR government and the obstacles posed by the Polish commanders resulted in the announcement of drafting of men born in 1896–98 only on 25 May, and never making it come into force practically. Only a partial mobilisation was conducted in the counties of the Dnister: Yampil and Mohyliv, where 6000 registrants gathered. Early in June, there were over 21,000 soldiers on board of the Ukrainian army, which meant around 10,000 active combatants.

After that reinforcement, the UPR army was to be organised in the triad system. Three sotnyas (companies) formed a kuren (battalion), three kurens – a brigade, and three brigades – an infantry division. Each of the divisions additionally included an artillery brigade, a cavalry regiment, a technical kuren (engineers) and various ancillary services. Early in June the army was composed of six infantry divisions: 1st Infantry Zaporizhska Division, 2nd Infantry Volynska Division, 3rd Infantry Zalizna Division, 4th Infantry Kyivska Division, 5th Infantry Khersonska Division, and 6th Sich Rifle Division. However, none of them reached full manpower, all were under strength. New units were added later, during the retreat: the Independent Cavalry Division and the 1st Machine Guns Division. Their firepower was strongly reinforced by the three armoured trains: Karmeluk, Zaporozhets, and Chernomorets. In the summer of 1920 the additional 1st Zaporozhe Independent Air Fleet, which operated eight reconnaissance airplanes of German make, was set up in Warsaw’s Pola Mokotowskie.

General Tadeusz Kutrzeba was right to notice that

from the operational point of view, we lost in Ukraine, as we were unable to defend it until the time when a Ukrainian army designed for that task could form.

The time was definitely far too short, as the Bolshevik 1st Cavalry Army of Semyon Budyonny broke the line of the front to the south of Kyiv already on 5 June 1920, and moved to the rear of the Polish armies. In reaction to that, Commander of the 3rd Army, General Edward Rydz-Śmigły ordered withdrawal from the city and retreat to the west.