The Battle for the Donbas was a military campaign of the Russian Civil War that lasted from January to May 1919, in which the White Army repulsed attacks of the Red Army on the territory of the Don Cossacks and occupied the Donbas region of eastern Ukraine after heavy fighting. The German withdrawal from the Donbas in November 1918 and the collapse of the Ukrainian State led to Pyotr Krasnov's White Armed Forces of South Russia advancing into the region. Lugansk fell on 19 November 1918; by 3 December, Debaltseve, Donetsk, and Mariupol were also in White hands. At the same time, the Reds successfully advanced into northern Ukraine, forcing Anton Denikin to transfer troops from the Volga region to the Donbas and Crimea to support the beleaguered Don Cossacks. In December 1918, Vladimir May-Mayevsky's 3rd Division was transferred from Stavropol to the Donbas to prevent the Red Army from gaining access to the North Caucasus in the rear of Denikin's army. On 12 January 1919, the Whites launched an offensive in the Donbas, taking Polohy from Nestor Makhno's Black Army on 20 January. The Black Guards suffered 1,000 losses during the fighting for Gulyai-Polye from 21 to 22 January, and Makhno was forced to withdraw to stabilize the front. On 14 January, however, the Reds occupied Starobilsk and entered the northern Donbas region. On 20 January, Innokentiy Kozhevnikov's Reds took Kostiantynivka and Bakhmut and attacked towards the Don from Lugansk a day later. Fighting occurred along the Mariupol-Donetsk-Bahmut-Lugansk line, and, on 8 February, the Makhnovists recaptured Polohy, threatening the Volunteer Army's flank. In mid-February, Denikin transferred more troops to the Lugansk region. On 24 February, the Reds began a successful offensive against Debaltseve, which depleted the Volunteer battalions after weeks of continuous fighting. On 12 March 1919, Jukums Vacietis ordered the Red Army's Ukrainian Front to join the Southern Front in liquidating the White Army in the Donbas region, but the Reds were distracted by Symon Petliura's advance to Kyiv and the Entente intervention along the Black Sea coast. On 20 March 1919, the Reds captured Donetsk, followed by Melitopol. The Allies withdrew from Kherson on 8 March and Mykolaiv on 16 March, enabling Makhno to seize Berdiansk on 15 March, Volnovakha on 17 March, and Mariupol on 29 March. On 27 March, Vacietis ordered a renewed offensive against the Donbas, and, on 29 March, 26,000 Red infantry, 3,300 Red cavalry, and 10,000 Makhnovists - soon to be joined by 10,000 bayonets and 200 cavalry from the 12th Rifle Division - began their offensive. The Whites counterattacked before the Red reinforcements could arrive, and the Whites retook Debaltseve on 30 March. The Reds were soon distracted by the Vyoshenskaya Uprising in the Don region, and the Soviet offensive grew exhausted. In May, the Reds launched a new offensive, retaking Lugansk on 15 May. However, a White Russian cavalry counterattack forced Makhno to retreat, and the Volunteer Army launched a counterattack which retook Donetsk, Avdiivka, and Debaltseve in late May. The Soviet 9th Army was cut in two and destroyed as a combat unit, and the Donbas region rested in White hands.