Hi Anthony,
Where to start...
St Albans has never, to my knowledge, been referred to as the "City of the Legions"
Chester WAS known in Welsh as "Caerlleon" and shares a name with Caerleon on Usk - both of which mean "City/Fortress of the Legions." It's been a longtime contender for Arthur's supposed ninth battle.
Both Chester and Caerleon have amphitheatres - Susan Cooper fans will recognise Caeleon's from "The Dark is Rising".
Arthur's battles are, of course, not mentioned at all in Gildas's "De Excidio et Conquestu Britanniae" because, famously, this ONLY contemporary account doesn't mention Arthur at all! I assume that he is actually referring to Nennius's ninth century Historia Brittonum.
Even if one was to take the medievel Round Table as anything other than fiction the number of knights seated at it (if you include the once off mentions in Geoffry of Monmouth) was, by reckoning (and I actually counted once - how sad am I) 135 or 136 depending on whether Balan and Balin are interchangable.
Pete
God is our guide! from field, from wave, From plough, from anvil, and from loom; We come, our country's rights to save, And speak a tyrant faction's doom: We raise the watch-word liberty; We will, we will,we will be free!