SERBIA (Srbiya), formerly an inland kingdom of south eastern Europe, situated in the north of the Balkan Peninsula, now incorporated in Yugoslavia (q.v.). The frontier, as defined by the Berlin Treaty of 1878, was, roughly speaking, indicated by rivers in the north, and by mountains in the south. In the north, between Verciorova and Belgrade, the Danube divided Serbia from Hungary for 157 m. ; and between Belgrade and the border village of Racha the Save divided it from Croatia-Slavonia for 8o m. In the north-west the Drina flowed for 102 m. between Bosnia and Serbia; in the north-east the Danube, for 5o m., and the Timok for 23 m., constituted respectively the Rumanian and Bulgarian boundaries. Various mountain ranges marked the frontiers of Bosnia on the west, Turkey on the south-west and south, and Bulgaria on the south and south-east. According to the survey carried out by the Serbian general staff in 1884 the area of the country was 18,782 sqm.
The Serbs (Srbi, as they call themselves) are a Slavonic nation, ethnically and by language the same as the Croats (Hrvati, Horvati, Croati). The Croats, however, are Roman Catholics and use the Latin alphabet, while the Serbs belong to the Ortho dox Church and use the Cyrillic alphabet, augmented by special signs for the special sounds of the Serb language. (See SLAVS.) The earliest mention of the Serbs is to be found in the ninth century; the origin of the name which appears alike in Lusatia and the Balkans is obscure. Nothing is known of their earlier history except that they lived as an agricultural people in Galicia, near the source of the river Dniester. In the beginning of the 6th century they descended to the shores of the Black Sea. Thence they began to move westerly along the left shore of the Danube, crossed that river and occupied the north-western corner of the Balkan Peninsula. According to the emperor Constantine Porphyrogenitus, the emperor Heraclius (610-64o) invited the Serbs to settle in the devastated north-western provinces of the Byzantine empire and to defend them against the incursions of the Avars. According to newer investigations, Heraclius only made peace with them, confirming them in the possession of the prov inces which they already had occupied, and obtaining from them at the same time the recognition of his suzerainty. Their known
history as a Balkan nation begins towards the middle of the 7th century.
This internal political process was complicated by the struggle between the Greek Church and Greek emperors on the one side and the Roman Catholic Church and the Roman Catholic Powers (Venice and Hungary) on the other, for the possession of exclu sive ecclesiastical and political influence. The danger increased when the Bulgarians came, towards the end of the 7th century, and formed a powerful kingdom on the eastern and south-eastern frontiers of the Serbs. Practically from the 8th to the 12th cen tury the bulk of the Serbs was under either Bulgarian or Greek suzerainty, while the Serbo-Croat provinces of Dalmatia acknowl edged either Venetian or Hungarian supremacy.