United Baltic Duchy

The proposed United Baltic Duchy, (German: Vereinigtes Baltisches Herzogtum, Estonian: Balti Hertsogiriik, Latvian: Apvienotā Baltijas hercogiste) also known as the Grand Duchy of Livonia, was a state proposed by the Baltic German nobility and exiled Russian nobility after the Russian Revolution and German occupation of the Courland, Livonian, and Estonian governorates of the Russian Empire.

The idea comprised the lands in Estonia and Latvia and included the creation of a Duchy of Courland and Semigallia and a Duchy of Estonia and Livonia that would be in personal union with the Crown of Prussia under the German Empire's occupied territory Ober Ost before the end of World War I covering the territories of the Medieval Livonia in what are now Latvia and Estonia.

During World War I the German Imperial Army had occupied the Courland Governorate of the Russian Empire by the autumn of 1915. The front stabilised along the line Riga–Daugavpils–Baranovichi.

Following the February Revolution of 1917 in Russia, the Russian Provisional Government declared the establishment of the Autonomous Governorate of Estonia on 12 April [O.S. 30 March] 1917, amalgamating the former Russian Governorate of Estonia and the northern portion of the Governorate of Livonia. After the October Revolution later in the same year, the elected Estonian Provincial Assembly declared itself the sovereign power in Estonia on 28 November 1917. On 24 February 1918, a day before the arrival of German troops, the Estonian Salvation Committee of the Provincial Assembly issued the Estonian Declaration of Independence. The Western Allies recognized the Republic of Estonia de facto in May 1918.

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