Assyria

 was a part of the Roman Empire by at least 64 AD, when the First Doctor, Vicki, Barbara and ian visited Byzantium. The historian Gemellus once told Ian that there was once an Assyrian King called Shalmaneser II who led an army of some 120,000 men to resist the Roman Empire, but they failed in spite of their size because they implied inadequate shields against the centurions. (PROSE: Byzantium!)