Possible Clues:

• Nineveh's empire
• Ancient kingdom
• Semiramis's realm
• Where the biblical lost tribes were held captive
• How silly one would be to get such an airy return to the old country
• Ancient empire along the Tigris
• Old empire, so small, insubstantial to overturn
• The old place could make the start of 16 across come back in an airy fashion
• Its host with their banners at sunset were seen
• Succeeded getting into a country, an ancient kingdom