This is almost
certainly the same as Megalopolis, which Pompey
founded (64 B.C.) in the southernmost region of Mithridates' former kingdom. Parts of the city's large territory
were transferred by Antony to Comana Pontica and
to the Galatian chieftain Ateporix. At a later stage
Megalopolis belonged to Pythodoris of Pontus. The
name Sebasteia is likely to commemorate a refoundation when the city was annexed to Galatia between
2-1 B.C. and A.D. 1-2. Sebasteia had metropolitan status
from the time of Verus. In Diocletian's reorganization
of the provinces it became metropolis of Armenia Prima.
Sebasteia evidently lay at or near modern Sivas on
the Kizil Irmak (Halys fl.). Excavation on the citadel
of Topraktepe in Sivas has revealed nothing Roman, and
the exact site remains to be discovered.
D. R. WILSON