Balkan Peninsula

   The southeasternmost peninsula of Europe, often referred to as the Balkans. On three sides it is bordered by seas: the Adriatic Sea, Ionian Sea, Mediterranean Sea, Aegean Sea, Sea of Marmora, and Black Sea (qq.v.). To the north, the Danube (q.v.) and Sava Rivers are its traditional northern limits. Maintaining control over the northern Balkans was essential for the protection of Greece and Constantinople (qq.v.). Nevertheless, geography and the peninsula's road systems conspired to make this difficult. The Danube was a boundary that could be penetrated. Once across the Danube, most mountain ranges run north-south, making invasion from the north relatively easy. Most road systems ran north-south as well, including the military road from the Danube (q.v.) frontier that ran from Belgrade to Nish (qq.v.), where it split into two branches: one going to Skopje and Thessalonike (qq.v.), the other in a more southeasterly direction to Serdica, then to Philippopolis, Adrianople, and Constantinople (qq.v.). The famous east-west highway called the Via Egnatia (q.v.) ran from Dyrrachion via Thessalonike to Constantinople (qq.v.). Thus, once the Danube was penetrated both geography and roads favored the invader. The history of the peninsula in Byzantine times can be viewed largely as a history of its invasions, e.g., by Visigoths, Avars, Slavs, Bulgars, Serbs, Rus, Pechenegs, Uzes, Crusaders, and Ottomans (qq.v.).