Bosnian Crisis
The Bosnian Crisis, also known as the Annexation Crisis (German: Bosnische Annexionskrise, Turkish: Bosna Krizi; Serbo-Croatian: Aneksiona kriza, Анексиона криза) or the First Balkan Crisis, erupted on 5 October 1908 when Austria-Hungary announced the annexation of Bosnia and Herzegovina, territories formerly within the sovereignty of the Ottoman Empire but under Austro-Hungarian administration since 1878. This unilateral action – timed to coincide with Bulgaria's declaration of independence from the Ottoman Empire on 5 October – sparked protestations from all the Great Powers and Austria-Hungary's Balkan neighbors, Serbia and Montenegro.