 This may be inferred from the Primary Chronicle which reports that Vladimir I of Kiev conquered the "Cherven towns" from the Poles in 981.The region returned to Polish sphere of influence in 1018, when Boleslaw I of Poland took the Cherven towns on his way to Kiev.Yaroslav I of Kiev reconquered the borderland in 1031, but was again ruled by Poland in 1069-1086; t remained part of Kievan Rus and its successor state of Halych-Volhynia until 1340 when it was once again taken over by Kingdom of Poland under Casimir III of Poland.