The South Slavs are a subgroup of Slavic peoples who speak the South Slavic languages.
They inhabit a contiguous region in the Balkan Peninsula, southern Pannonian Plain and eastern Alps, and are geographically separated from the body of West Slavic and East Slavic people by the Romanians, Hungarians, and Austrians. The South Slavs include the Bosniaks, Bulgarians, Croats, Macedonians, Montenegrins, Serbs and Slovenes. They are the main population of the Central and Southern European countries of Bulgaria, Bosnia and Herzegovina, Croatia, Republic of Macedonia, Montenegro, Serbia and Slovenia. Their territories have been separated from the rest of the Slavic nations since the 15th century by the modern non-Slavic states of Austria, Hungary, Romania and Moldova, leading to a differing historical progression for the South Slav nations in relation to the West and East Slavs.
In the 20th century the country of Yugoslavia (lit. "South Slavia") merged the vast region to which most South Slavic nations are autochthonous (with the key exception of Bulgaria and the Bulgarians) into a single state. The concept of Yugoslavia, as a single state for all South Slavic peoples, emerged in the late 17th century and gained prominence through the Illyrian movement of the 19th century. The name was coined as a combination of the Slavic words jug (south) and sloveni (Slavs).
The battle of Berzitia (Bulgarian: Битката при Берзития) occurred in the fall of 774 near the region of Berzitia, Macedonia. The result was a Byzantine victory.
After an unsuccessful campaign of the Byzantine Emperor Constantine V earlier that year, the Bulgarian Khan Telerig decided to strike back to the southwest and sent a small raiding army of 12,000 to capture Berzitia.
The Byzantine emperor was informed for the raid in due time by his spies in Pliska and gathered an enormous force. Near the town the Byzantines surprised the Bulgarian Army and after a long fight they managed to defeat them due to their much larger superiority in troops.
Constantine V was eager to follow-up his success and led another campaign against the Bulgarians, but once again it failed. However, Telerig learned during this event that all his plans were known to Constantine through a network of spies within his government. He decided to eliminate them once and for all and sent a message to Constantine, stating that he was going to flee in exile to Constantinople. In exchange, Telerig asked the emperor to reveal the spies to his associates in Pliska for their own safety. As Telerig was not the first ruler to flee to Constantinople, Constantine revealed his information and sent the Bulgarian government the list of spies, however Telerig deceived him and did not travel to Constantinople. When Telerig learned of their names he executed them all and eliminated the Byzantine spy network within his government.