Castles in Britain

[Quintus.JC]

For maximum efficiency; convert both Inverness and Caernaveron to cities. If you have already united the British isles then there will be no internal threat. Concentrate on making Nottingham the troop production centre for your kingdom, preferable with an archery guild.

[Zild]

Ditto. These days I often convert Caen to a city as well, as Nottingham is close enough and more advanced.