Ukraine's 3rd Army Corps completes two stages of covert Operation Vivaldi near Lyman, retaking 125 km²
Ukraine's 3rd Army Corps publicly confirmed and completed two stages of Operation Vivaldi, a covert offensive in northern Donetsk Oblast near Lyman that began in May under information silence. The operation liberated 125 km² of territory, including several settlements, and reportedly halted the Russian "northern claw" advance.
Key points
- Operation Vivaldi ran from May in northern Donetsk Oblast and was publicly confirmed on 15 September by 3rd Army Corps commander Andrii Biletsky.
- Two stages have been completed: the first liberated Novoselivka, Oleksandrivka, Yarova, the outskirts of Korovii Yar and Serednie; the second added Drobysheve, Derylove and Shandryholove.
- In total, 125 km² of territory was returned, of which 50 km² was fully de-occupied.
- The 3rd Army Corps asked Western OSINT analysts to stop publishing geolocations of the advance; analysts agreed, and French cartographer Clément Molin first detected signs of the operation on satellite imagery at the end of May.
- Ukrainian sources report the first battlefield deployment of ground robotic complexes (NRK) for demining and assault support; near Shandryholove, NRK cleared 30 km of routes in two nights.
- Russia's elite Rubikon drone unit was reportedly withdrawn from the Lyman-Borova direction due to heavy losses, and Biletsky said the 20th and 25th Russian armies suffered a rout on the Lyman salient.
- Russia's MoD claimed on 22 September that its 'Centre' grouping had encircled Dobropillia; ISW and DeepState rejected the claim, noting no Russian evidence was provided.
Why it matters
Ukrainian reporting describes Operation Vivaldi as one of the most significant successful Ukrainian offensive operations of 2026, retaking 125 km² (with 50 km² fully de-occupied) in northern Donetsk Oblast and disrupting Russian plans to encircle Ukraine's "belt of fortress cities" in the Donbas. The operation was carried out under a comprehensive OPSEC regime that kept it hidden from Russian command until mid-September — including a request to Western OSINT analysts to stop publishing geolocation data — and is being cited as a milestone in Ukrainian drone and ground-robotic warfare.
What happened
Ukraine's 3rd Army Corps, commanded by Andrii Biletsky, publicly confirmed and completed two stages of Operation Vivaldi, a covert offensive in northern Donetsk Oblast near Lyman that had been underway since May under information silence. During the first stage, Ukrainian forces liberated Novoselivka, Oleksandrivka, Yarova, the outskirts of Korovii Yar and Serednie, and cleared 75 km² of territory with 10 km² fully de-occupied. The second stage added Drobysheve, Derylove and Shandryholove, bringing the total to 125 km² returned, of which 50 km² was fully de-occupied. Biletsky said the operation effectively routed Russia's "northern claw" and halted the Russian offensive on the Lyman direction, and that the 20th and 25th Russian armies and the elite Rubikon drone unit suffered devastating blows; the 3rd Corps reported Rubikon had been withdrawn from the Lyman-Borova direction. The 3rd Army Corps also announced what it described as the first battlefield deployment of ground robotic complexes (NRK) for demining and assault support, clearing 30 km of routes in two nights near Shandryholove, and noted that NRK currently neutralize about 60% of anti-personnel mines in its area of responsibility. Separately, units of the 1st Corps of the National Guard "Azov" carried out an operation beginning in early August that derailed a Russian attempt to reach logistics routes for encircling Druzhkivka and striking toward Dobropillia, with the 3rd Army Corps reporting total Russian losses of 237 personnel (193 killed, 44 wounded, 3 captured) in that action. Ukrainian forces also cleared territory near Toretske on the Dobropillia direction and regained a section near Zapadne on the Kupiansk direction, according to DeepState analysts.
How Ukrainian sources describe it
Ukrainian coverage centres on the 3rd Army Corps and its commander Andrii Biletsky, presenting Vivaldi as a successful, well-prepared offensive that outclassed Russian forces and as a milestone in Ukrainian drone and robotic warfare. Reporting emphasises the operation's information silence and OPSEC — including the request to Western OSINT analysts not to publish geolocations — and the fact that Russian command and milbloggers were caught unaware, with Russian milbloggers such as Rybar and Anatoliy Radov reportedly republishing Western OSINT content read by the Russian MoD. DeepState analyst Roman Pohorily frames Russian efforts on the Lyman direction as "multiplied by zero" and warns of continued Russian pressure on Mykolaivka south of Lyman. Ukrainian sources contrast ISW and DeepState assessments of Russian losses with the Russian MoD's 22 September claim that its 'Centre' grouping had encircled Dobropillia, noting that ISW refuted the claim and DeepState reported Ukrainian gains near Toretske. Several articles highlight tactical and technical innovations: the first battlefield use of ground robotic complexes (NRK) for demining, the "pairs under drone cover" tactic borrowed from Russian practice, and the parallel Azov operation that derailed a Russian attempt to encircle Druzhkivka and strike toward Dobropillia, with named Azov units credited.
Where reporting differs
The Russian Ministry of Defence claimed on 22 September that units of its 'Centre' grouping had encircled Dobropillia and were advancing toward Oleksandrivka, without providing maps or other evidence; the Institute for the Study of War refuted this claim, and DeepState analysts reported that Ukrainian forces had cleared territory near Toretske on the Dobropillia direction.
Background
The Ukrainian advance on the Lyman direction had been ongoing since May 2026 but was kept out of public reporting until 15 September, when 3rd Army Corps commander Andrii Biletsky confirmed the offensive and named it Operation Vivaldi. The 3rd Army Corps spent more than half a year before Vivaldi stabilising the front from Borova to Lyman and restructuring command, personnel, reconnaissance, drones and logistics. At the start of the operation, the corps asked Western OSINT analysts, including @moklasen and French cartographer Clément Molin, to stop publishing geolocations of Ukrainian advances; analysts agreed, and Molin first detected signs of fighting on the Lyman salient via satellite imagery at the end of May. Russian milbloggers such as Rybar and Anatoliy Radov reportedly republish Western OSINT content and are read by the Russian MoD, a pattern that contributed to Russian command not noticing the operation's progress. On 1 September, Russia publicly claimed to have "taken" Sviatohirsk while its General Staff and Vladimir Putin were reportedly unaware of the Ukrainian operation near Lyman. After being stopped north of Lyman, Russian forces redeployed some troops south of Lyman and began pressing on Mykolaivka, which DeepState analyst Roman Pohorily described as a key stronghold before Sloviansk.