TRISTAN AND ISOLDE
Dunluce Castle, County Antrim, Ireland
Historical Setting: Dark Ages of Britain, after the Roman empire had deserted them. So, sometime after 410 CE and before the 600s when we know the Saxons had control over Britain
Note: This isn't a critique on how closely the movie stayed to the original legend (for those who must know, they deviated from it totally and completely), this is about critiquing what the movie presented to us as historical fact. So it doesn't matter that Tristan and Isolde, side-story to the Arthurian legends (who ran away and hid in Camelot for a bit) didn't mention Arthur at all. No Arthur. Now, as I mentioned in my historical review of King Arthur there is a lot of evidence to support the theory that one man was able, for a while, to fill the void left by the Romans before the Saxons took control. His name could have been Arthur, could have been Marke like it was in this movie. Doesn't matter.
First off, the terms "England" and "English" would not have been used to describe the people inhabiting Britain at this time. Both derive from the Angle people who, with the Saxons, conquered Britain in the 600s CE. If they needed to use one term for the island they should have stuck with what the Romans called it. And for the people, Briton was probably a more time appropriate term.
The terms "Ireland" and "Irish" are also not very likely. More like Erie and Celt.
Ireland had NO kings. They were a pastoral people. Some men claimed the title, but there was no central power on the island.
The Picts, who inhabited the Northern part of Scotland, were mentioned a lot in this movie, but I sure didn't see any. The word "Pict" may come from the Latin words for painted or tattooed. Julius Caeser (though not the best source) mentions that the Pits liked to stain their faces and bodies blue. Considering the Picts were supposed to be fighting the Irish Celts in this movie it was very weird that no one had any face paint on them at all. Also, the Picts stayed a separate and independent people until their conversion in the 7th century CE.
Dunlace Castle, home of the Irish King in the movie, was built in the 13th century, some 900 years after the movie's time frame.
Considering the Saxons later conquer Britain, it was more than a little odd to see them as a part of the British alliance. The Saxons were the enemy of the Dark Ages, an enemy the Romanized-Celts of Britain eventually lost to. Something a little more historical would be the British tribes trying to ally against the Saxons.
The way that Catholicism in Ireland was portrayed was all wrong. When Catholicism first came to Ireland it merged with Ireland's pagan beliefs and became something called Irish Catholicism. The Church in Rome used the British conquest of Ireland to try and stamp it out, and the Potato Famine pushed the last adherents of Irish Catholicism into the arms of Roman Catholicism. The difference between the two religions was discipline, where Roman Catholicism was a more disciplined religion than Irish Catholicism. Irish Catholicism was more monks living in solitude and people worshipping on their land. The first convent in Ireland was not opened until Christmas Day, 1777 CE, so I think it's safe to say it wouldn't have been opened for Isolde to visit in the 400s CE.