Russian annexation of Donetsk, Kherson, Luhansk and Zaporizhzhia oblasts in the context of "Brianka"

Russia, the largest country in the world by area, has international land borders with fourteen sovereign states as well as two narrow maritime boundaries with the United States and Japan. There are also two breakaway states bordering Russia, namely Abkhazia and South Ossetia. The country has an internationally recognized land border running 22,407 kilometres (13,923 mi) in total, and has the second-longest land border of any country in the world, after China (22,457 kilometres (13,954 mi)).

The borders of the Russian Federation (formerly the Russian SFSR) were mostly drawn since 1956 (save for minor border changes, e.g., with China), and have remained the same after the dissolution of the Soviet Union. In 2014, Russia annexed Ukraine's Crimean peninsula and parts of Donetsk and Luhansk oblasts in a move that remains internationally unrecognized, but which altered de facto borders with Ukraine. In 2022, Russia further annexed Donetsk, Kherson, Luhansk and Zaporizhzhia oblasts further changing de facto borders with Ukraine.

The Russia–Ukraine border is the de jure international boundary between Russia and Ukraine. Over land, the border spans five Russian oblasts and five Ukrainian oblasts. Due to the ongoing Russo-Ukrainian War, which began in early 2014, the de facto border between Russia and Ukraine is different from the legal border recognized by the United Nations. As of 2024, Russia is militarily occupying a significant portion of Ukraine, and Ukraine is militarily occupying a very small portion of Russia.

According to a 2016 statement by Viktor Nazarenko, the head of the State Border Guard Service of Ukraine, the Ukrainian government did not have control over 409.3 kilometres (254.3 mi) of the international border with Russia. This stretch of land was formerly controlled by pro-Russian separatists under the Donetsk People's Republic and the Luhansk People's Republic (see War in Donbas), both of which were annexed by Russia in September 2022, seven months after the beginning of the ongoing Russian invasion of Ukraine. Ukraine has also not had authority over the Kerch Strait since 2014, when Russia annexed Crimea; the Ukrainian administration was pushed out of Crimea and Russian checkpoints were set up at the boundary with Kherson Oblast.

Zaporizhzhia Oblast (Ukrainian: Запорізька область, romanized: Zaporizka oblast), commonly referred to as Zaporizhzhia (Запоріжжя), is an oblast (region) in south-east Ukraine. Its administrative centre is the city of Zaporizhzhia. The oblast covers an area of 27,183 square kilometres (10,495 sq mi), and has a population of 1,638,462 (2022 estimate). The oblast is an important part of Ukraine's industry and agriculture.

Most of the oblast's area, including all of the coast, has been under Russian military occupation since the 2022 Russian invasion of Ukraine, although the capital and the majority of the population have remained under Ukrainian administration. In September 2022, Russia declared it had annexed the Zaporizhzhia oblast based on the results of a disputed referendum. The referendum and subsequent annexation are not internationally recognized.

The Luhansk People's Republic (LPR; Russian: Луга́нская Наро́дная Респу́блика (ЛНР), romanised: Luganskaya Narodnaya Respublika (LNR), IPA: [lʊˈɡanskəjə nɐˈrodnəjə rʲɪˈspublʲɪkə]) is a disputed territory administered as a republic of Russia in the occupied parts of eastern Ukraine's Luhansk Oblast, with its capital in Luhansk. The LPR was proclaimed by Russian-backed paramilitaries in 2014, and it initially operated as a breakaway state until it was annexed by Russia in 2022. The entire territory of LPR is viewed as sovereign territory of Ukraine by nearly all UN member states. It has a population of 2,102,921 (2022 estimate).

Following Ukraine's Revolution of Dignity in 2014, pro-Russian, counter-revolutionary unrest erupted in the eastern part of the country. Russia annexed Crimea from Ukraine, while the armed separatists seized government buildings and proclaimed the Luhansk People's Republic (LPR) and Donetsk People's Republic (DPR) as independent states. This sparked the war in Donbas, part of the wider Russo-Ukrainian war. The LPR and DPR were often described as puppet states of Russia during this conflict. They received no international recognition from United Nations member states before 2022.

Russian separatist forces in Ukraine, primarily the People's Militias of the Donetsk People's Republic (DPR) and the Luhansk People's Republic (LPR), were pro-Russian paramilitaries in the Donbas region of eastern Ukraine. They were under the overall control of the Russian Federation. They were also referred to as Russian proxy forces. They were active during the war in Donbas (2014–2022), the first stage of the Russo-Ukrainian War. They then supported the Russian Armed Forces against the Ukrainian Armed Forces during the 2022 Russian invasion. In September 2022, Russia annexed the DPR and LPR, and began integrating the paramilitaries into its armed forces. They are designated as terrorist groups by the government of Ukraine.

The separatist paramilitaries were formed during the 2014 pro-Russian unrest in Ukraine. The Donbas People's Militia was formed in March 2014 by Pavel Gubarev, who proclaimed himself "People's Governor" of Donetsk Oblast, while the Army of the South-East was formed in Luhansk Oblast. The Donbas war began in April 2014 after these groups seized Ukrainian government buildings in the Donbas, leading the Ukrainian military to launch its Anti-Terrorist Operation against them.

Luhansk (UK: /luːˈhænsk/, US: /-ˈhɑːn-/; Ukrainian: Луганськ, IPA: [lʊˈɦɑnʲsʲk] ), also known as Lugansk (UK: /-ˈɡæn-/, US: /-ˈɡɑːn-/; Russian: Луганск, IPA: [lʊˈɡansk] ), is a city in the Donbas in eastern Ukraine. As of 2022, the population was estimated to be 397,677 (2022 estimate), making Luhansk the 12th-largest city in Ukraine.

Luhansk served as the administrative center of Luhansk Oblast, before pro-Russian separatists seized control of the city in 2014 and made it the capital of the self-proclaimed Luhansk People's Republic. The Ukrainian administration was located in Sievierodonetsk from 2014 to 2022 during the war in Donbas, due to Ukraine not being in control of Luhansk. Sievierodonetsk was captured by Russia in 2022 and Luhansk Oblast was later annexed by Russia in late 2022.

Antratsyt (Ukrainian and Russian: Антрацит) is a city in Rovenky Raion, Luhansk Oblast (region), Ukraine. Residence of Antratsyt urban hromada. Until 1962 it was known as Bokove-Antratsyt. Its population is approximately 52,150 (2022 estimate).

Since early 2014, Antratsyt has been under the occupation of the self-proclaimed Luhansk People's Republic until its illegal annexation into Russia in 2022.

Khrustalnyi or Krasnyi Luch is a city in Luhansk Oblast, eastern Ukraine. Its population is approximately 79,533 (2022 estimate). It has historically been one of the most important coal mining locations in the Donbas region.

The city was founded in the 1880s after the discovery of coal deposits in the region, and grew over the following century. Until 1920, it was known as Kryndachivka, after the surname of an early settler. It was a site of fighting during World War II. Since the beginning of the Russo-Ukrainian War in 2014, it has been occupied by the widely unrecognized Luhansk People's Republic and later by Russia after its Annexation on 30 September 2022.