The answers are modern sovereign states which were partly or wholly legally controlled by the Russian and Soviet Empires. States that were invaded but not annexed appear as bonus answers.
Alaska (1799-1867); Fort Elizabeth, Hawaii (1816-17); Fort Ross, California (1811-41)
1799-1991
Kazakhstan (1799-1991)
1802-1991
Georgia (1802-1918, 1921-91)
1806-1807
Kotor (1806-07)
1806-1991
Axerbaijan (1806-1918, 1920-91)
1808
Gotland (1808)
Years in Empire
Modern Country
Regions Controlled
1812-1991
Bessarabia (1812-1918, 1940-91)
1815-1916
Poland (1815-1916)
1828-1991
Armenia (1828-1918, 1921-91)
1854-Present
South Kuril Islands - Still occupied (1854-1875, 1945-2012)
1868-1991
Bukhara, Khiva & Kokand (1868-1991)
1871-1955
Eastern Railroad Zone (1898-1905, 1945-55); Ili (1871-81); Manchuria (1900-05, 1945-46); Port Arthur (1898-1905, 1945-55); Tientsin Concession (1903-20)
1876-1991
Kyrgyzstan (1876-1991)
1878-1917
Kars (1878-1917; Western Armenia (1915-17)
1881-1991
Turkmenistan (1881-1991)
1895-1991
Tajikistan (1895-1991)
1944-1947
Bulgaria (1944-1947)
1944-1947
Hungary (1944-47)
1945-1948
North Korea (1945-1948)
1945-1955
Austria Soviet Zone (1945-55); Vienna Soviet Zone (1945-55)
1945-1990
Berlin Soviet Zone (1945-90); Germany Soviet Zone (1945-55)
1942-1946
Berlin Soviet Zone (1945-90); Germany Soviet Zone (1945-55)
1979-1989
Berlin Soviet Zone (1945-90); Germany Soviet Zone (1945-55)
1968
Berlin Soviet Zone (1945-90); Germany Soviet Zone (1945-55)
18th-20th C
Berlin Soviet Zone (1945-90); Germany Soviet Zone (1945-55)