Eastern Ukraine campaign in the context of "Battle of Sievierodonetsk (2022)"

On 24 February 2022, Russia invaded Ukraine, starting the largest and deadliest war in Europe since World War II. It is a major escalation of the war between the two countries that began in 2014. The fighting has caused hundreds of thousands of military casualties and tens of thousands of Ukrainian civilian casualties. As of 2025, Russian troops occupy about 20% of Ukraine. From a population of 41 million, about 8 million Ukrainians had been internally displaced and more than 8.2 million had fled the country by April 2023, creating Europe's largest refugee crisis since World War II.

In late 2021, Russia massed troops near Ukraine's borders and issued demands to the West, including a ban on Ukraine ever joining NATO. After repeatedly denying having plans to attack Ukraine, on 24 February 2022, Russian president Vladimir Putin announced a "special military operation", saying that it was to support the Russian-backed breakaway republics of Donetsk and Luhansk, whose paramilitary forces had been fighting Ukraine in the war in Donbas since 2014. Putin espoused irredentist and imperialist views challenging Ukraine's legitimacy as a state, baselessly claimed that the Ukrainian government were neo-Nazis committing genocide against the Russian minority in the Donbas, and said that Russia's goal was to "demilitarise and denazify" Ukraine. Russian air strikes and a ground invasion were launched on a northern front from Belarus towards the capital Kyiv, a southern front from occupied Crimea, and an eastern front from the Donbas towards Kharkiv. Ukraine enacted martial law, ordered a general mobilisation, and severed diplomatic relations with Russia.

The siege of Mariupol began on 24 February 2022 and lasted until 20 May, as part of the Russian invasion of Ukraine. It saw fighting between the Russian Armed Forces (alongside the Donetsk People's Republic People's Militia) and the Ukrainian Armed Forces for control over the city of Mariupol in southeastern Ukraine. Lasting for almost three months, the siege ended in a victory for Russia and the Donetsk People's Republic, as Ukraine lost control of the city amidst Russia's eastern Ukraine offensive and southern Ukraine offensive; all Ukrainian troops remaining in the city surrendered at the Azovstal Iron and Steel Works on 20 May 2022, after they were ordered to cease fighting.

Mariupol is located in Ukraine's Donetsk Oblast, and following the siege, it was initially controlled by the Donetsk People's Republic, supported by occupying Russian troops. However, it was later subjected to Russia's annexation of southeastern Ukraine, and remains under direct Russian control as of 2024.