Treaty of Saint Petersburg
Treaty of Saint Petersburg, signed in 1875 between Japan and Russia, stipulated that Japan gives up any right on Sakhalin island and in exchange gains all the Kuril islands until Kamchatka peninsula.The Treaty of Shimoda left Sakhalin territory without well defined borders, which led to incidents between Russian and Japanese settlers. In order to remedy this situation the Japanese government sent an ambassador, Takeaki Enoboto to St Petersburg to define Sakhalin territory clearly.
See also: Kuril Island conflict