Oster

Oster Остер
City
Saint Michael's Church
Seal
Oster Show map of Chernihiv Oblast Oster Show map of Ukraine
Coordinates: 50°56′55″N 30°52′52″E / 50.94861°N 30.88111°E / 50.94861; 30.88111
Country	Ukraine
Oblast	Chernihiv Oblast
Raion	Chernihiv Raion
Hromada	Oster urban hromada
First mentioned	1098
Magdeburg rights	1662
Area
• Total	76 km2 (29 sq mi)
Elevation	111 m (364 ft)
Population  (2022)
• Total	5,564

Oster (Ukrainian: Остер, IPA: [osˈtɛr]; Russian: Остёр, romanized: Ostyor) is a city in Chernihiv Raion, Chernihiv Oblast, Ukraine. It is located where the Oster River flows into the Desna. Oster hosts the administration of Oster urban hromada, one of the hromadas of Ukraine.^[1] Its population is 5,564 (2022 estimate).^[2]

Today Oster is a river port with a cotton-textile factory and a food industry. Some parts of the old fortress in Oster have been preserved, as have the remains of the Saint Michael's Church, constructed in 1098 and the only preserved church of the medieval principality of Pereiaslav.

Oster was founded in 1098 by Vladimir II Monomakh as Gorodets, a fortress belonging to the Pereiaslav principality, which was later inherited by his son Yuri Dolgorukiy. In 1240, it was destroyed by the Mongol invasion, after which it remained in ruins for a century. After the destruction of the fort, a village was built in its place, named Stary Oster or Starogorodkaya. In the beginning of the 14th century, a newer settlement arose closer to the Desna, named Oster.

From 1356 Oster was under control of the Grand Duchy of Lithuania, and from 1569 under the Union of Lublin which was part of the Polish–Lithuanian Commonwealth. In 1648, it became part of an uyezd (county) of the Pereiaslav regiment. From 1654, Oster was under control of Russia. In 1622, King Jan II Casimir granted Oster the Magdeburg rights and a coat of arms. After harsh battles of the Khmelnytsky Uprising, Polish rule was again established in Oster, but in February 1664, with support from the local population, the Poles were driven back by Cossacks and the Russians. In 1803, the city became an uyezd center of Chernigov Governorate.

Until 18 July 2020, Oster belonged to Kozelets Raion. The raion was abolished in July 2020 as part of the administrative reform of Ukraine, which reduced the number of raions of Chernihiv Oblast to five. The area of Kozelets Raion was merged into Chernihiv Raion.^[3][4]