Leningrad Oblast of two great lakes of the European Part of Russia, Lake Ladoga and Lake Onega. Its northeastern part, between the Gulf of Finland and Lake Ladoga, occupies the Karelian Isthmus. Some islands in the Gulf of Finland (including Kotlin, on which the city of Kronstadt has been built) and Lake Ladoga (including Konevets) also belong to the oblast. Much of the area of the oblast belongs to the drainage basin of the Neva, which is the only outflow of Lake Ladoga. Whereas the Neva, which flows to the Gulf of Finland (the city of Saint Petersburg is located in its
Staraya Ladoga his successor Oleg. The Heimskringla and other Norse sources mention that in the late 990s Eric Haakonsson of Norway raided the coast and set the town ablaze. Ladoga was the most important trading center in Eastern Europe from about 800 to 900 CE, and it is estimated that between 90% to 95% of all Arab dirhams found in Sweden passed through Ladoga. Ladoga's next mention in chronicles is dated 1019, when Ingigerd of Sweden married Yaroslav of Novgorod. Under the terms of their marriage settlement, Yaroslav ceded Ladoga to his wife, who appointed her father's cousin, the Swedish earl Ragnvald