dear Mr.Cornwell, I loved your arthur books. I have one question though. why were the armies so small? a couple of thousands of soldiers to invade Britain (mynydd baddon).
The armies were small because society was much smaller, and because raising large armies takes an immense amount of logistical skill - large armies have to be fed, watered, organised, and that requires a professional bureaucracy and a strong central government. The Romans had that, and could field vast armies, but in Dark Age Britain there's nothing but small kingdoms and chaos.