Kharkiv in the context of "Treaty of Brest-Litovsk (Ukraine–Central Powers)"

Ukraine is a country in Eastern Europe. It is the second-largest country in Europe after Russia, which borders it to the east and northeast. Ukraine also borders Belarus to the north; Poland and Slovakia to the west; Hungary, Romania and Moldova to the southwest; and the Black Sea and the Sea of Azov to the south and southeast. Kyiv is the nation's capital and largest city, followed by Kharkiv, Odesa, and Dnipro. Ukraine's official language is Ukrainian.

Humans have inhabited Ukraine since 32,000 BC. During the Middle Ages, it was the site of early Slavic expansion and later became a key centre of East Slavic culture under the state of Kievan Rus', which emerged in the 9th century. Kievan Rus' became the largest and most powerful realm in Europe in the 10th and 11th centuries, but gradually disintegrated into rival regional powers before being destroyed by the Mongols in the 13th century. For the next 600 years the area was contested, divided, and ruled by a variety of external powers, including the Grand Duchy of Lithuania, the Kingdom of Poland, the Polish–Lithuanian Commonwealth, the Austrian Empire, the Ottoman Empire, and the Tsardom of Russia.

A radio telescope is a specialized antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum, just as optical telescopes are used to make observations in the visible portion of the spectrum in traditional optical astronomy. Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night.

Since astronomical radio sources such as planets, stars, nebulas and galaxies are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment. Radio telescopes are typically large parabolic ("dish") antennas similar to those employed in tracking and communicating with satellites and space probes. They may be used individually or linked together electronically in an array. Radio observatories are preferentially located far from major centers of population to avoid electromagnetic interference (EMI) from radio, television, radar, motor vehicles, and other man-made electronic devices.

Kharkiv Raion (Ukrainian: Харківський район) is a raion (district) of Kharkiv Oblast in eastern Ukraine. Its administrative center is the city of Kharkiv. Population: 1,729,049 (2022 estimate).

On 18 July 2020, as part of the administrative reform of Ukraine, the number of raions of Kharkiv Oblast was reduced to seven, and the area of Kharkiv Raion was significantly expanded. One abolished raion, Derhachi Raion, as well as Liubotyn Municipality, part of Nova Vodolaha Raion, and the city of Kharkiv, which was previously incorporated as a city of oblast significance and did not belong to the raion, were merged into Kharkiv Raion. The January 2020 estimate of the population of the former Kharkiv Raion was 176,186 (2020 est.).

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.

Marcin Kitz (1891–1943) was a Polish-Jewish painter.

Marcin Kitz started his painting studies in Lwów at Stanisław Rejchan and Stanisław Batowski Kaczor, 1919/1920 at Jan Matejko Academy of Fine Arts in Kraków, he studied also in Berlin, Munich and Vienna. Since 1923 he participated on the painting salons in Kraków, Lwów, Poznań and Warsaw. 1939-1941 he lived in Moscow, Kharkiv and Kiev.

Kharkiv Tractor Plant (KhTZ or HTZ) (Ukrainian: Харківський тракторний завод, ХТЗ, romanized: Kharkivskyi Traktornyi Zavod) is an agricultural machinery manufacturer in the Ukrainian city of Kharkiv. Established in 1930–31, as a centerpiece of Stalin's First Five-Year Plan for Soviet industrialization (1927–32), KhTZ was Ukraine's largest tractor manufacturer, producing both wheeled and tracked tractors. In 2016, the Ukrainian security service (SBU) alleged that at the Kremlin's direction the Russian owners were planning to decommission the enterprise. The industrial plant was reported destroyed by extensive shelling and resulting fires on the fourth day of the Russian invasion of Ukraine in February 2022.

From the end of February 2014, in the aftermath of the Euromaidan and the Revolution of Dignity, which resulted in the ousting of Russian-leaning Ukrainian president Viktor Yanukovych, demonstrations by Russian-backed, pro-Russian, and anti-government groups (as well as pro-government demonstrations) took place in Crimea, Donetsk, Luhansk, Kharkiv and Odesa. The unrest, which was supported by the Russian military and intelligence services, belongs to the early stages of the Russo-Ukrainian war.

During its first phase in February–March 2014, the Ukrainian territory of Crimea was invaded and subsequently annexed by Russia following an internationally unrecognized referendum, with the United Nations General Assembly voting in favor of Ukraine's territorial integrity. Concurrently, protests by anti-Maidan and pro-Russian groups took place across other parts of eastern and southern Ukraine. Local separatists, some directed and financed by the Russian security services, took advantage of the situation and occupied government buildings in Donetsk, Luhansk, and Kharkiv oblasts in early March 2014. The Ukrainian government was able to quickly quell this unrest, and removed the separatists by 10 March.

Izium or Izyum (Ukrainian: Ізюм, IPA: [iˈzʲum] ; Russian: Изюм) is a city on the Donets River in Kharkiv Oblast, eastern Ukraine that serves as the administrative center of Izium Raion and Izium urban hromada. It is about 120 kilometres (75 mi) southeast of the city of Kharkiv, the oblast's administrative center.

Izium has a population of 44,979 (2022 estimate), making it the second-most populous city in Kharkiv Oblast behind Kharkiv proper. It has held economic significance for centuries due to its position as a transportation link between Kharkiv and the Donbas region to the southeast.