Smaller medieval states could struggle to concentrate their soldiers

The shrinking Eastern Roman Empire and fragmented Carolingian territories fielded smaller offensive armies than earlier emperors. Even so, the ninth-century Byzantine establishment is put at about 120,000 regular troops supported by roughly 8 million people. About 25,000 belonged to the field army, with 95,000 distributed among 20 military districts or themes. In the west, smaller expeditionary armies did not necessarily mean fewer soldiers overall. Rulers could struggle to command the magnates responsible for bringing contingents, while towns and rural communities retained their own armed populations.