evidence: Bolshoy Ussuriysky Island on the Amur river is essentially part of Khabarovsk and the Khabarovsk region. Once upon a time, it was home to houses, summer cottages, and agricultural and ship-repair enterprises. Russia and China quarreled over Bolshoy Ussuriysky Island for more than 150 years, after drawing the border along the Amur river. (The river itself belonged to neither country, and the status of its islands remained undetermined.) In 1929, the USSR took complete control of the island, formally putting the territory "under protective custody." During the Second World War, Japanese troops occupied the island, but the Soviet Union later reclaimed it. In 1964, the Chinese government launched negotiations to regain the territory, and these talks only concluded in 2004, when Russia signed an agreement handing over 170 of the island’s 350 square kilometers (65 of 135 square miles). The deal entered force a year later, and the border was fully in place by October 2008. From that moment, Bolshoy Ussuriysky Island has been divided into two parts: one Chinese and the other Russian.