Can anyone clarify the relationships between the following: Icenia/Caercolum/Caerwent/Anglica?

I'm confused after reading some entries in the GPC and The Boy King. I know that after 500 this region becomes Anglica. Prior to that is looks like it, or part of it, was called Icenia for the Iceni tribe. The GPC indicates that it is a dukedom called Caercolum, but then shows a division where the souther part is Caercolum and the northern part is a county called Caerwent. But isn't Caerwent in Cambria? ???

See GPC page 31.

Caercolun is a DUCHY that includes the COUNTIES of Caercolun and Caerwent, and a part of the Fens. Personally, I'd go on calling the Duchy as Icenia (I think that was the term in the Boy King), and the two counties under it as Caercolun and Caerwent, to avoid the confusion betwene the Duchy of Caercolun and the County of Caercolun. The whole lot becomes Anglia when the Angles conquer it and purge it of the Cymri(c nobility).

Think of it as the State of New York that includes the cities of New York and Albany, for instance.

As for the town of Caerwent in Monmouthshire, Wales, this is just an instance of the etymologies being related. Caer = castle. Gwent = Venta from Latin Venta Silurum "Market town of the Silures", while the Icenian Caerwent comes from Venta Icenorum, modern-day Caistor St Edmund in Norfolk. At least, that is my best guess until Greg speaks up to let us know why he named the county so. :)

All clear now? :)