The Last Legion is a throwback to 1960s Italian sword-and-sandal stuff, a bad history lesson explaining how, in 480 AD, a ragged regiment of Romans commanded by Colin Firth was roaming in the gloaming around Hadrian's Wall after the fall of the empire and provided the basis for King Arthur's kingdom. The last Caesar becomes Pendragon, father of Arthur, a sword made for Julius Caesar turns into Excalibur, and two-fisted sorcerer Ambrosinus (Ben Kingsley) changes his name to Merlin.