Political Union
Even political unions of the 20th century, such as Yugoslavia , were not always matched by feelings of the ethnic or cultural accord, nor did the sharing of communism during World War II necessarily provide more than a high-level political and economic alliance.
In the 3rd century BC, the Celtic tribe known as the Scirii established themselves in today’s Ukraine. After being conquered by Rome in 167 BC, the Scirii became Roman allies and remained under Roman rule until the 4th century AD. During this period, the Romans gradually assimilated the local population.
In the 2nd century BC, the Germanic tribes began migrating westwards into the territory of present-day Germany, Belgium, Netherlands, and France. These tribes include the Vandals, Burgundians, Franks, Alemanni, Goths, Lombards, Saxons, Frisians, Jutes, Angles, Britons, Irish, and Scots.
During the Migration Period, Germanic tribes entered Eastern Europe through the Carpathian Mountains. They spread throughout the territories of present-day Slovakia, Hungary, Czech Republic, Slovenia, Croatia, Serbia, Bosnia and Herzegovina, Montenegro, Bulgaria, Romania, Moldova, and Ukraine.
After the fall of the Western Roman Empire in the 5th century AD, the Germanic tribes continued expanding westward. One such tribe was the Ostrogoths, who invaded Italy and occupied much of its territory for nearly two centuries. Another important Germanic tribe was the Visigoths, who ruled Spain during the same time.
After the collapse of the Ostrogoth Kingdom in Italy in the late 7th century, the Byzantine Empire took control of the Balkans. However, the Byzantines failed to establish a strong presence in the region, and the Slavic tribes resumed their expansion.
By the 8th century, the Slavs controlled large portions of central and eastern Europe.East Central and Eastern Europe in the Middle Ages. In the 9th century, they were divided into three major kingdoms: Great Moravia (in present-day western Slovakia), Kievan Rus’ (in present-day northern Ukraine), and Bulgaria.
Byzantine Emperor Basil II launched an invasion against Bulgaria in 1018. He defeated the Bulgarian ruler Boris III at the Battle of Kleidion in 1040. This marked the end of the First Bulgarian Empire. The Bulgarians retreated to the Rhodopes mountains, where they formed a new state called Despotate of Epirus.