Montenegro, mountainous region in the Balkans which largely preserved its autonomy at the time of the Ottoman Empire. Up to 1918 a neighbour of Austria-Hungary (Bosnia and Herzegovina), Montenegro achieved independence in the 18th century with the help of Austria and Russia, and participated as their ally in the Turkish War of 1788-1791. From the middle of the 18th century the Njegoš family were hereditary princes; Montenegro's independence was recognised by the Great Powers and its territory enlarged at the Berlin Congress of 1878; Montenegro became a kingdom in 1910. During the two Balkan Wars of 1912/13 and in the First World War (1914-1918) Montenegro sided with Serbia and became part of Yugoslavia in 1918. As such, it turned into a republic within the Federation in 1963. After the dissolution of Yugoslavia, Montenegro and Serbia joined to form the new Federal Republic of Yugoslavia.