Ancient Bulgaria

thumb|Roman head of a Dacian of the type known from Trajan's Forum, AD 120–130, marble, on 18th-century bust|313x313px

thumb|350px|Roman Moesia in 250 AD, divided into the provinces of Moesia Superior to the west and Moesia Inferior to the east

ancient region surrounded by the Danube at the north and west and the Black Sea at the east

Roman bridge over the Danube (completed in 328)

military expedition into European Scythia by Achaemenid king Darius I in 513 BCE.