Slavonia is a region in Eastern Croatia. It is a fertile agricultural and forested lowland bounded, in part, by the Drava River in the north and the Sava River in the south. Wheat and corn are the major crops, and the leading industry is food processing. It also has some oil and natural gas resources.
The region was originally part of the Roman province of Pannonia. In the 7th century a Slavic state owing allegiance to the Avars was established. With Croatia, Slavonia was united within Hungary in 1102. It came under Turkish rule in the 16th century and was recovered by Hungary from the Turks through the Treaty of Karlowitz (1699). Southern parts of it became part of the Austria-Hungary's Military Frontier. As a result of the Revolution of 1848, Hungary lost Slavonia, which was made an Austrian crownland, but in 1868 Slavonia was restored to the Hungarian crown and united with Croatia. It became part of Yugoslavia in 1918. When the Yugoslav constituent republic of Croatia declared its independence in 1991, Serbs of Krajina established their own state over portions of eastern and western Slavonia. By late 1995 Serbs retained control of only Eastern Slavonia, which was integrated into Croatia by January 1998.
The area is divided in five counties, total population of 781,454 (2001). The biggest city is Osijek with a population of 105,074 (2001). Other cities are Slavonski Brod, Vinkovci, Vukovar, Đakovo, Požega, Virovitica, Nova Gradiška, Slatina, Županja, Našice, Valpovo, Belišće.
A subspecies of pedunculate (common) oak quercus robur slavonica is named after Slavonia. The region is home to these and sessile oaks.