Location of Pannonia
Pannonia was a province of the Roman Empire located in western Hungary, eastern Austria, northern Croatia, northwestern Serbia, northern Slovenia, western Slovakia, and northern Bosnia and Herzegovina. With a capital of Sirmium (Sremska Mitrovica, Serbia), the region bordered the Danube River and was one of the border provinces on the eastern edge of the empire. In 107 AD, it was divided into Pannonia Superior and Pannonia Inferior, two separate provinces.