The Far East is Russia's 'wild east, ' where hardened Cossacks in the early 17th century - and young Soviets (and Gulag prisoners) in the 20th - came to exploit the region's untapped natural resources - such as gold of the Kolyma, diamonds of Sakha and oil off Sakhalin. Russian explorers and plunderers even leapfrogged from the Pacific coast and Kamchatka to stake claims on parts of what is today the USA.
Much ado locally is made about Anton Chekhov's (occasionally whoring) trip through the Far East to Sakhalin in 1890. WWII gets much tribute in regional mu- seums, but so does the Russo-Japanese War, which humiliated Russia and ended with Japan taking the southern half of Sakhalin Island in 1905; the USSR got it back after WWII. China and the USSR had their diplomatic burps too, like outright battling over a worthless river island near Khabarovsk in 1969.
In June 2005 Russia and China finally settled a four-decade dispute over their 4300km border by splitting 50-50 the Bolshoy Ussurysky and Tarabarov Islands near the junction of the Amur and Ussuri Rivers, outside Khabarovsk.