Izium or Izyum (Ізюм, Изюм), iˈzjum) is a city on the Donets River in Kharkiv Oblast, eastern Ukraine. It serves as the administrative center of Izium Raion. Izium hosts the administration of Izium urban hromada, one of the hromadas of Ukraine. It is about southeast of the administrative center of the oblast, Kharkiv. Izium had a population of During the Russian Invasion of Ukraine, Russian forces occupied the city in April 2022. However, the city was recaptured by Ukrainian forces in the 2022 Kharkiv counteroffensive. In 1681, a Cossack fortress was built within a small settlement, which marks the foundation date of Izium. It grew to be an important defense against Tatar invasions of the region. In 1684 the five-domed Baroque cathedral of the Saviour's Transfiguration was built. The cathedral was renovated in 1902 and restored in 1955. In 1765, Izium became a city, and in 1780 became an administrative center of Izyumsky Uyezd, one of the subdivisions of the Kharkov Governorate of the Russian Empire. The churches of Ascension (1819–21) and of St. Nicholas (1809–23) rank among the finest Neoclassical buildings in the region. In the second half of the 19th century, the city's main exports were wool, sold to Kharkiv and Poltava, and building materials sold to Taganrog. During World War II, Izium was the site of numerous important battles. A Red Army salient was cut off by counterattacking German forces (during the Second Battle of Kharkiv) and was eliminated in one of the most expensive learning errors for the Red Army. Izium was occupied by the German Army from 24 June 1942 until it was liberated on 5 February 1943. The Germans operated a Nazi prison in the city. Izium expanded rapidly in the 20th century due to its importance as a junction between Kharkiv and the Donets Basin. In January 1989 the population was 64,334 people, up from 12,000 in 1926. In January 2013, its population was 51,511 people. To comply with decommunization laws, the local "Lenin Square" was renamed "John Lennon Square" in February 2016.