In a Russification drive in the 1840s, Nicholas I prohibited use of the Belarusian language in public schools, campaigned against Belarusian publications and tried to pressure those who had converted to Catholicism under the Poles to reconvert to the Orthodox faith. In 1863, economic and cultural pressure exploded in a revolt, led by Konstanty Kalinowski. After the failed revolt, the Russian government reintroduced the use of Cyrillic to Belarus in 1864 and no documents in Belarusian were permitted by the Russian government until 1905.
During the negotiations of the Treaty of Brest-Litovsk, Belarus declared independence under German occupation on 25 March 1918, forming the Belarusian People's Republic. The choice of the name was probably based the fact that the educated core of the newly formed government was educated in the tsardom universities, with a corresponding education around the ideology of West-Russianism. Despite the territory continually being dominated by the German Imperial Army and the remnants of Imperial Russian Army in the final year of the World War, and then the BolshevikRed Army. The German administration allowed schools with Belarusian language, previously banned in Russia; a number of Belarusian schools were created but the economy was heavily influenced by the Germans as part of the Mitteleuropa plan.
The frontiers between Belarus and the former Russian Empire were not recognized by the other world powers. In its Third Constituent Charter, the following territories were claimed for Belarus: Mogilev Governorate (province), as well as Belarusian parts of Minsk Governorate, Grodno Governorate (including Belastok), Vilna Governorate, Vitebsk Governorate, and Smolensk Governorate, and parts of bordering governorates populated by Belarusians, rejecting the then split of the Belarusian lands between Germany and Russia. The areas were claimed because of a Belarusian majority or large minority (as in Grodno and Vilna Governorate), although there were also numbers of Lithuanians, Poles and people speaking mixed varieties of Belarusian, Lithuanian and Polish, as well as many Jews, mostly in towns and cities (in some towns they made up a majority). Finally the Treaty of Minsk established Belarus' boundaries, gaining territory from Soviet Russia that was outside the Brest-Litovsk lines but lost Vilna to Lithuania and Ukraine.