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.
History
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.
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]