There was a film many years ago called "Arthur, The Young Warlord", a British
thing starring (if memory serves and it may not) Oliver Tobias. It was very
Dark Ages, concerned mostly Arthur and the Saxons. Low budget, but there was
a feel too it that except for the bobbed hair of their Gwynhwfr they may have
gotten some of it right.
It included an interesting scene of both sides licking their swords to prove
their weapons were not poisoned. Strange.
I have only seen it on TV once, and that perhaps 14 years ago, but I have a
copy I taped of it somewhere and will see if I can find it and whether or not
there's still a signal left on the tape after all these years.