Pannonia

Pannonia, a province of the Roman empire, conquered between 35 B.C. and A.D. 8; occupied a square with the Danube on the N. and E. and the Save almost on the S. border; it passed to the Eastern Empire in the 5th century, fell under Charlemagne's sway, and was conquered by the modern Hungarians shortly before A.D. 1000.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)