It wasn't on the top of my list, but since I enjoyed the stories of King Arthur and the knights, I gave it a try. I almost turned it off after the first 5 minutes because it oozed with the stench of the Catholic bashing. From the equating Roman bloodlust and greed to the Church in Rome, to the championing of Pelagius.
Off the cuff, the dates seemed all wrong. The movie used 300 A.D. for the date of the Roman conquest of the Samartians. But the Roman soldiers were bearing the Christus Rex emblem (a P and X combined) but Constantine didn't issue the Edict of Milan until 313. And that only allowed Christians to worship legally, it didn't throw the empire under the hand of the Church. Paganism was still legal and two thirds of the government remained pagan. So I hardly could imagine the soldiers running under the Christian banner early in the fourth century.
I decided to stick it out and see if the "hero" Arthur stayed true to his Christian beliefs he professed. I was sadly disappointed there also. Besides proclaiming Pelagius to be an all around great Christian focused on free will and equality for all people, the movie also claimed he was excommunicated and put to death. The excommunication was true, but he was also restored for some time after he professed his faith to Pope Zosimus. The excommunication was later renewed as his heretical teachings became clear. He eventually was expelled from Palestine in 418 and wasn't heard from again.
Now as fiction, a movie can be what it wants with a mythical character such as Arthur. But the lede, insinuated that recent archaeological evidence was the basis for this movie. The underlying theme was this was the "true" King Arthur.
But with all his noble ideals and devotion to Pelagius (who attracted the morally stringent type) Arthur didn't seem to have a problem with fornication or a pagan burial and druid style wedding at the end.
There is plenty of gore and blood spattering in the battle scenes. But aside from that, (and that isn't that compelling to most) there isn't much to captivate in this movie.