The ninth and final Russo-Turkish War started in 1877, the same year the Ottomans withdrew from the Constantinople Conference. Romania then declared its independence and waged war on Turkey, joined by Serbians and Bulgarians and finally the Russians (see also History of Russia (1855–92)). Austria occupied Bosnia in 1878. The Russians and the Ottomans signed the Treaty of San Stefano in early 1878. After deliberations at the Congress of Berlin, which was attended by all the Great Powers of the time, the Treaty of Berlin (1878) recognized several territorial changes.