SAO Eastern Slavonia, Baranja and Western Syrmia

The Serbian Autonomous Oblast of Eastern Slavonia, Baranja and Western Syrmia (Srpska autonomna oblast Istočna Slavonija, Baranja i Zapadni Srem, Српска аутономна област Источна Славонија, Барања и Западни Срем) was a self-proclaimed Serb political entity in eastern Croatia, established during the Yugoslav Wars. It was one of three Serb Autonomous Oblasts (SAOs) proclaimed on the territory of Croatia. The region included parts of geographical regions of Slavonia, Baranja and Syrmia.

The entity was formed on 25 June 1991, the same day the Socialist Republic of Croatia decided to withdraw from Yugoslavia, following the Croatian independence referendum, 1991. In the first phase of the Croatian War of Independence, in 1992 the region joined the breakaway Republic of Serbian Krajina (RSK).

History
The SAO Eastern Slavonia, Baranja and Western Syrmia was declared on June 25, 1991, and on June 26 its first president was declared to be Goran Hadžić. Like the SAO Krajina, it was developed by the Serbian National Council, but was the one representing Eastern Slavonia, Baranja and Western Syrmia.

Initially, it was a separate Serb autonomous region (oblast), but subsequently joined the Republic of Serbian Krajina (RSK) in February 1992. Its borders were established by the end of 1991 as entrenched front lines of the first phase of the Croatian War of Independence. Up to August 1995, Eastern Slavonia, Baranja and Western Syrmia was de facto part of the Republic of Serbian Krajina, while de jure still a part of Croatia, per United Nations Security Council Resolution 753. The region did not have its own local regional administration within RSK.

Geography
Territory of former Eastern Slavonia, Baranja and Western Syrmia was part of the Central European Pannonian Basin. The eastern border of region was mostly the Danube river, while approximately one third of the western border was the Drava river. The Kopački rit natural preserve located near the confluence of Drava and Danube formed a major geographical barrier - there were no road or rail connections between Baranja and the southern parts of the territory, except through Serbia.

Other boundaries were not natural boundaries: the border with Hungary in the north had existed since the Kingdom of Serbs, Croats and Slovenes, the eastern border with FR Yugoslavia partly existed since the Kingdom of Slavonia (on the Danube) and was partly set with the formation of SFR Yugoslavia, while the border with the rest of Croatia in the west and south was formed after the fronts were settled in the first phase of the Croatian War of Independence.

Eastern Slavonia is a mostly flat area, with the best type of soil where agriculture is highly developed, particularly on wheat fields, and it also has several forests as well as vineyards.

The Đeletovci Oil fields are located between the villages of Đeletovci, Banovci and Nijemci.

Traffic over the Brotherhood and Unity Highway (today the A3) was interrupted with the formation of the ESBWS. The water transport over the Danube river continued unobstructed. The Drava river was not navigated at the time. The railway line between Zagreb and Belgrade and the transport between the Budapest and Sarajevo passing through the area were also closed.

Population
The population of this area was ethnically mixed. Before the war, the total population of the area numbered 192,163 inhabitants, and was composed of:
 * 90,454 (47%) Croats,
 * 61,492 (32%) Serbs, and
 * 40,217 (21%) others (Hungarians, Roma, Yugoslavs, Germans, Rusyns, Slovaks, etc.).

During the 1991-1995 War in Croatia, 109,500 Serbs lived in this area out of a total of 160,000.

Municipalities and Inhabited places
During the existence of the Republic of Serbian Krajina, the region was divided into five municipalities:
 * Beli Manastir (in Baranja),
 * Dalj and Tenja (in eastern Slavonia), and
 * Vukovar and Mirkovci (in western Syrmia).

The main cities in the area were Vukovar and Beli Manastir. Other important places included Borovo Selo, Darda, Dalj, Ilok, and Tenja.

Legacy
After the RSK's demise in August 1995, the region was reconstituted again as Eastern Slavonia, Baranja and Western Syrmia (1995-1998).

Following the November 1995 Erdut Agreement, it was subsequently controlled by the United Nations Transitional Administration for Eastern Slavonia, Baranja and Western Sirmium

Today the ethnic Serb interests in the region are advocated by the Joint Council of Municipalities.