After the signing of the peace treaty with the Central Powers in Brest-Litovsk, the leadership of the Ukrainian People’s Republic (UPR) resolved to establish control over Crimea—even before the arrival of Austro-German troops. Although Crimea was not formally part of the UPR, Ukrainian authorities considered it Ukrainian territory, a position reflected in internal government discussions and documents of the Council of People’s Ministers. The UPR also sought to bring the Black Sea Fleet under its control.

On 10 April 1918, the Crimean Group of the Ukrainian Army was formed from units of the Zaporizhzhia Division, under the command of Colonel Petro Bolbochan. Its mission was to reach and secure the Crimean Peninsula before the allied forces—particularly the 52nd Corps of Special Designation led by German General Robert von Kosch—could establish their presence.

On 18 April, the forces of the Ukrainian People’s Republic (UPR) captured Melitopol after overcoming resistance from the Bolsheviks. The offensive pressed on without pause: on 21 April, Ukrainian troops entered Novooleksiivka, then launched a swift nighttime assault on the crossings over the Syvash. A detachment led by Sotnyk (Captain) Zilynskyi broke through a mined bridge using motorized rail trolleys, eliminated the guards, and, under cover from the armored trains of Semen Loshchenko and Pavlo Shandruk, which provided continuous machine-gun and artillery fire, disabled the explosives.

The speed and decisiveness of the attack shattered the morale of the Bolshevik defenders: Ukrainian infantry swiftly occupied the trenches, and the enemy, gripped by panic, abandoned their positions. Remarkably, not a single soldier from Zilynskyi’s detachment was killed in the operation.

Determined to maintain momentum and prevent the enemy from regrouping, Colonel Petro Bolbochan chose not to wait for the arrival of the main forces and pressed on with the pursuit. By the evening of 22 April, the Crimean Group defeated a Bolshevik defensive line near Dzhankoi—a key railway junction in northern Crimea—and entered the city, which German troops had already occupied.

Detachments of Crimean Tatar insurgents, who had risen up against Bolshevik rule, began joining Bolbochan’s forces as they advanced. These uprisings had been unfolding in parallel with the offensive by Ukrainian and allied forces. On 24 April, Ukrainian troops entered Simferopol, followed the next day by the capture of Bakhchysarai. Meanwhile, the Kost Hordiienko Haidamak Cavalry Regiment, led by Colonel Vsevolod Petrov, was making its way through the mountainous routes toward Sevastopol. On 28 April, the unit engaged in combat with Bolshevik forces near the city. As a result, on 29 April, the Black Sea Fleet raised Ukrainian flags and declared allegiance to the government of the Ukrainian People’s Republic in Kyiv.

However, the uncoordinated advancement of the Ukrainian army caused tension with the German command. On 26 April, German forces blockaded all Ukrainian positions in Simferopol and issued an ultimatum to Colonel Bolbochan: surrender arms and immediately withdraw from Crimea. The Crimean Group withdrew from the peninsula on 27 April following intense negotiations. They left with their weapons, regimental banners, and a significant amount of captured equipment, redeploying to the outskirts of Melitopol.

Despite its conclusion, the Crimean campaign showcased the brilliant military leadership of Colonel Petro Bolbochan and remains one of the most remarkable episodes in the history of the Ukrainian armed forces.

Although Ukrainian troops were present in Crimea, the Ukrainian State lacked real political influence over the Crimean Regional Government, led by Suleiman Sulkevych. De jure, this government remained independent until November 1918 and consistently refused to join the Ukrainian State. The government of Hetman Skoropadskyi attempted to exert political and financial pressure to integrate Crimea, but negotiations between Kyiv and the Crimean authorities never resulted in a formal agreement on autonomy. Talks were ultimately interrupted by the outbreak of the anti-Hetman uprising and the advance of the Ukrainian People’s Republic’s Directorate.