< Yorkshire may have been the capital on Btiain 5,000 years ago. >
Dunno about it being the capital of all Britain, but we know it was the capital of northern England/lowland Scotland for a thousand years or more - though not quite sure they'd have seen it in the sense of capital cities as we see things today. The Grassington-to-Ilkley region was incredibly important in pre-Celtic times: hence the huge amount prehistoric remains. & you'll obviously know about Isurium as the capital of Brigantia - itself the largest pre-christian British kingdom.
Wot gets me is that we have in Yorkshire alone: the biggest standing stone in the country; the biggest stone row in the country; the largest henge in the country; the greatest amount of cup&ring art in the country; the largest concentration of prehistoric tombs in the country (I truly could go on) - but the archaeological fraternity prefer to sit on their arses down south & put money into things much less ancient, and on sites that have been stripped to the bone. Find a little tomb on Salisbury Plain & they throw cash at it. Find a full prehistoric settlement in Yorkshire, with graveyard, ritual sites & more besides.....and.....oh dear - there doesn't appear to be any cash for it... (sorry - I'm on my usual rant)
Bring the projector stuff along BN & we'll see if we can use it. If not, I'm sure we can arrange for such talks for future gatherings.