The Treaty of Saint Petersburg (; ) between the Empire of Japan and the Russian Empire was signed on 7 May 1875, and its ratifications exchanged at Tokyo on 22 August 1875. The treaty itself went into effect in 1877. Its terms stipulated that Japan cedes to Russia the part of Sakhalin island it then owned in exchange for the group of the Kuril Islands owned by Russia (between Iturup island and the Kamchatka Peninsula). Consequently, Sakhalin island as a whole became Russian territory, and the entire Kuril archipelago Japanese territory. The authentic text of the treaty is written in French. Differences with its Japanese translation contributed to the controversy on what constitutes the Kuril islands, claims to which Japan renounced in 1951 by the Treaty of San Francisco. The Treaty of Saint Petersburg (1875) is part of an ongoing, and long-standing, territorial dispute between Russia and Japan over the jurisdiction of the Kuril Islands. Background Golovnin Incident In 1811, Vasily Golovnin, a Russian explorer tasked by Tsar Alexander I with mapping the Kuril Islands, was captured by the Japanese. When Golovnin and his crew aboard the ship Diana approached Kunashir Island, they were taken ashore and imprisoned for violating Sakoku, or Japanese isolationist policies. Golovnin and his crew were held prisoner for two years and were released in 1813. This event, known as the Golovnin Incident, demonstrated that the border between Russia and Japan was too vague for the Russian Empire, and that to avoid another episode such as Golovnin's, the border needed to be clearly defined. Treaty of Shimoda The Treaty of Shimoda of 1855 had defined the border between Japan and Russia to be the strait between Iturup (Etorofu) and Urup (Uruppu) islands in the Kurile chain, but had left the status of Sakhalin (Karafuto) open. Without well-defined borders, incidents between Russian and Japanese settlers began to occur. In order to remedy this situation, the Japanese government sent an ambassador, Enomoto Takeaki, to Saint Petersburg to clearly define the border in this area. After a year of negotiations, Japan agreed to renounce its claims to Sakhalin, with compensation for Japanese residents, access by the fishing fleet to the Sea of Okhotsk, ten-years free use of Russian ports in the area and ownership of all of the Kuril Islands. The Japanese Ministry of Foreign Affairs still cites this treaty as a reason to define the northern borders. Russo-Japanese