anising several revolts, most notably the First (1598) and Second Tarnovo Uprisings (1686) and Karposh's Rebellion (1689). In the 18th century, the Enlightenment in Western Europe provided influence for the initiation of a movement known as the National awakening of Bulgaria. It restored national consciousness and became a key factor in the liberation struggle, resulting in the 1876 April Uprising. Up to 30,000 Bulgarians were killed as Ottoman authorities put down the rebellion. The massacres prompted the Great Powers to take action. They convened the Constantinople Conference in 1876, but their decisions were rejected by the Ottomans. This allowed the Russian Empire to seek a solution by force without risking military confrontation with other Great Powers, as had happened in the Crimean War. In 1877 Russia declared war on the Ottoman empire and defeated its forces with the help of Bulgarian volunteers.
Third Bulgarian state
The Treaty of San Stefano was signed on 3 March 1878, setting up an de jure autonomous Bulgarian principality on the territories of the Second Bulgarian Empire. The Great Powers immediately rejected the treaty out of fear that such a large country in the Balkans might threaten their interests. The subsequent Treaty of Berlin provided for a much smaller state comprising Moesia and the region of Sofia, leaving large populations of Bulgarians outside the new country. This played a significant role in forming Bulgaria's militaristic approach to foreign affairs during the first half of the 20th century.
The Bulgarian principality won a war against Serbia and incorporated the semi-autonomous Ottoman territory of Eastern Rumelia in 1885, proclaiming itself an independent state on 22 September 1908. In the years following independence, Bulgaria increasingly militarised and was often referred to as "the Balkan Prussia". Between 1912 and 1918, Bulgaria became involved in three consecutive conflicts—two Balkan Wars and World
