Balkan Wars, 1912-13, two short wars, fought for the possession of the European territories of the Ottoman Empire. The outbreak of the Italo-Turkish War for the possession of Tripoli (1911) encouraged the Balkan states to increase their territory at Turkish expense. Serbia and Bulgaria accordingly concluded (1912), with the aid of Russian secret diplomacy, a treaty of alliance. In a secret annex, the treaty provided for joint military action and the division of prospective conquests. The outbreak of the war (Oct., 1912), in which Greece and Montenegro joined the original allies, was followed by the speedy expulsion of the Turks from all of European Turkey, except the Constantinople area. After the conclusion of hostilities Serbia showed intentions of annexing a large part of Albania, in order to gain an outlet on the Adriatic, but this step toward a "Greater Serbia" was opposed by Austria-Hungary and Italy and by the Albanians, who had proclaimed their independence. Conferences of the ambassadors of the Great Powers at London created (1913) an independent Albania of fair size, thus cutting Serbia off from the sea. Dissatisfied with these terms, Serbia demanded of Bulgaria a greater share of Macedonia. Bulgaria thereupon attacked (June, 1913) Serbia, only to be attacked by Romania, Greece, and Turkey. As a result of this Second Balkan War, Bulgaria lost territory to all her enemies by the Treaty of Bucharest (Aug., 1913). The Balkan Wars prepared the way for World War I by satisfying some of the aspirations of Serbia and thereby giving a great impetus to the Serbian desire to annex parts of Austria-Hungary; by alarming Austria and stiffening Austrian resolution to crush Serbia; and by giving causes of dissatisfaction to Bulgaria and Turkey.

Balkan Peninsula, southeasternmost peninsula of Europe, c.200,000 sq mi (518,000 sq km), bounded by the Black Sea, Sea of Marmara, Aegean Sea, Mediterranean Sea, Ionian Sea, and Adriatic Sea. Although there is no sharp physiographic separation between the peninsula and Central Europe, the line of the Sava and Danube rivers is commonly considered as the region's northern limit. The Balkan Peninsula therefore includes most of Slovenia, Croatia, and Serbia, and Bosnia and Herzegovina, Montenegro, Albania, Macedonia, continental Greece (including the Peloponnesus), Bulgaria, European Turkey, and SE Romania. These countries, successors to the Ottoman Empire, are called the Balkan States. Historically and politically the region extends north of this line to include all of Slovenia, Croatia, Serbia, and Romania.

The peninsula is very mountainous; the main ranges are the Dinaric Alps, the Balkans, the Rhodope Mts., and the Pindus. Except for the barren Karst plateau in the northwest and the eroded highlands of Greece, the mountains are densely forested. The Morava, Vardar, Strimón, Mesta, and Maritsa are the largest rivers. The Morava and Vardar river valleys form the chief corridor across the peninsula. The mild Mediterranean-type climate, with its dry summer period, is limited to the southern and coastal areas. Covering a greater area are the humid subtropical climate in the northwest and the harsher humid continental climate in the northeast. The region as a whole is largely agricultural; fruits, grains, and grazing are important. A variety of mineral deposits are found there, including iron ore, coal, manganese, copper, lead, and zinc.

The peoples of the Balkan Peninsula make up several racial groups. However, linguistic and religious differences are more distinct than the racial divisions. The peninsula, at the crossroads of European and Asian civilizations, has a long history; Ancient Greece, the Byzantine Empire, and the Ottoman Empire flourished there.

Balkan Entente, loose alliance formed in 1934 by Yugoslavia, Romania, Greece, and Turkey to safeguard their territorial integrity against Bulgarian revisionism. It thus was in harmony with the Little Entente (formed by Yugoslavia, Romania, and Czechoslovakia chiefly against Hungarian revisionism). The events of World War II caused the dissolution of the Balkan Entente.

(1912–13) Two military conflicts that deprived the Ottoman Empire of almost all its remaining territory in Europe. In the First Balkan War, the Balkan League defeated the Ottoman Empire, which, under the terms of the peace treaty (1913), lost Macedonia and Albania. The Second Balkan War broke out after Serbia, Greece, and Romania quarreled with Bulgaria over the division of their joint conquests in Macedonia. Bulgaria was defeated, and Greece and Serbia divided up most of Macedonia between themselves. The wars heightened tensions in the Balkans and helped spark World War I.

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or Balkan Peninsula

Peninsula, southeastern Europe. Located between the Adriatic Sea, the Mediterranean Sea, and the Aegean and Black seas, it contains many countries, including Slovenia, Croatia, Bosnia and Herzegovina, Macedonia, Serbia, Montenegro, Albania, Moldova, Romania, and Bulgaria. From 168 BC to AD 107, part of the area was incorporated into Roman provinces, including Epirus, Moesia, Pannonia, Thrace, and Dacia. It was subsequently settled by Slavic invaders, Serbs, Croats, Slovenes, and Slavonized Bulgars, the last of whom were pushed into the Balkan region in the 6th century. It was gradually organized into kingdoms, many of which were overrun by the Ottoman Empire in the 14th–15th century. The factional strife that occurred there from the early 20th century, provoking the continual breakups and regroupings of different states, introduced the word balkanize into English.

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Bulgarian Stara Planina

Mountain range, southeastern Europe. It extends east to west across central Bulgaria from the Black Sea to the Serbian border; the highest point is Botev Peak, at 7,795 ft (2,376 m). The range forms the major divide between the Danube River in the north and the Maritsa River in the south. It is crossed by about 20 passes (notably Shipka Pass), several railway lines, and the Iskur River.

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