evidence: Russia and China signed a landmark deal on July 21, officially ending all outstanding territorial disputes between the two countries. Under the agreement, Russia will hand over Yinlong Island (known as Tarabarov in Russia) and half of the Heixiazi Island (Bolshoi Ussuriysky) at the confluence the of Amur and Ussuri rivers, clearing the way for closer strategic and economic relations with China. The deal flowed from an initial agreement signed in 2004 by former Russian President Vladimir Putin that proposed a 50-50 division of the disputed islands. While Russia returns Yinlong and half of Heixiazi, totalling 174 square kilometres, China has given up its claim to the other half of Heixiazi. [...] Negotiations between the two countries over the status of Heixiazi took place in 1964. Beijing demanded acknowledgement of the "unjust" character of all the seizures of territories by Russia since the nineteenth century. Moscow refused to discuss the issue. The second round of talks in 1969 ended abruptly with the eruption of armed clashes over Zhengbao (Damansky) Island in the Ussuri River. Both sides massed millions of troops along their borders as tensions escalated.