Treaty of Saint Petersburg
The Treaty of Saint Petersburg was signed in 1875 between Japan and Russia. Its terms stipulated that Japan give up any right on Sakhalin island in exchange for the Kuril islands up to the Kamchatka peninsula.
The Treaty of Shimoda left Sakhalin's territory without well defined borders, leading to incidents between Russian and Japanese settlers. In order to remedy this situation the Japanese government sent an ambassador, Enomoto Takeaki, to St Petersburg to clearly define Sakhalin territory.