Belarusian nationalism refers to the belief that Belarusians should constitute an independent nation. Belarusian nationalism began emerging in the mid-19th century, during the January Uprising against the Russian Empire. Belarus first declared independence in 1917 as the Belarusian Democratic Republic, but was subsequently invaded and annexed by the Russian Soviet Federative Socialist Republic in 1918, becoming part of the Soviet Union. Belarusian nationalists both collaborated with and fought against Nazi Germany during World War II, and protested for the independence of Belarus during the late 1980s and early 1990s.