 On the basis of its belief that it was an extension of Hokkaido, both geographically and culturally, Japan again proclaimed sovereignty over the whole island (as well as the Kuril Islands chain) in 1845, in the face of competing claims from Russia.In 1849, however, the Russian navigator Gennady Nevelskoy recorded the existence and navigability of the strait later given his name, and – in defiance of the Qing and Japanese claims – Russian settlers began establishing coal mines, administration facilities, schools, and churches on the island.In 1853–54, Nikolay Rudanovsky surveyed and mapped the island.