Sub-Roman Britain (Cavalry etc)

[Ron Andrea]

Yes, while the Romans seldom dictated local customs--in fact seemed to favor local power structures--they did try to maintain a monopoly on military force. Until late in the Roman period, there wouldn't have been "local militia" to go on being what they were. The Romans basically marched out and said, "Oh, by the way, see to defending yourselves." The Britons would have looked around and found some retired Roman soldier, some local lordling's house guard and some quasi-militia's in the fringe.

Mounted warriors would have been small bands with local loyalties, hardly the type to ride from one end of the isle to the under rallying local defenders. Some one like Ambrosius may have tried to raise such a force, but apparently it was not a long-lasting attempt. Y Godiddin indicates that, after a couple of centuries, the mounted warrior ideal was alive (but failed to defeats the Germans).

They did the best they could with what they had, which is why Vortigern employed the Roman practice of hiring federati against the Picts. It wasn't a bad idea, he just didn't have the depth of treasure to fund it.