The Kosovo Vilayet remained part of the Ottoman Empire. Austria-Hungary was allowed to station military garrisons in the Ottoman Vilayet of Bosnia and the Sanjak of Novi Pazar. The Vilayet of Bosnia was placed under Austro-Hungarian occupation although it formally remained part of the Ottoman Empire until it was annexed by Austria-Hungary thirty years later, on 5 October 1908. The Austro-Hungarian garrisons in the Sanjak of Novi Pazar were withdrawn in 1908, after the annexation of the Vilayet of Bosnia and the resulting Bosnian Crisis, to reach a compromise with the Ottoman Empire, which was struggling with internal strife because of the Young Turk Revolution (1908). The chaotic situation in the Ottoman Empire also allowed Bulgaria to formally declare its independence on 5 October 1908.