ancient empire in SW Asia in the region of the upper Tigris River: at its height (7th cent. ), it extended from the head of the Persian Gulf to Egypt and Asia Minor: original cap. Ashur; later cap. Nineveh
See Assyria in American Heritage Dictionary 4
(ə-sîrˈē-ə)
An ancient empire and civilization of western Asia in the upper valley of the Tigris River. In its zenith between the ninth and seventh centuries B.C. the empire extended from the Mediterranean Sea across Arabia and Armenia.