* CreatorCameo: Neil Marshall plays the archer that shoots [[spoiler: Bothos]] as he's riding towards Hadrian's Wall.
* TheDanza: Leonidas, played by Dimitri Leonidas.
* DatedHistory: It's a matter of some academic disagreement whether the Ninth Legion disappeared in Britannia. Neil Marshall was aware of the controversy but was more interested in telling the story of the legend than spot-on historical accuracy.
* DuelingMovies: With ''Film/TheEagle'', which is based on the same legend about the Ninth Legion, though it's adapted from [[Literature/TheEagleOfTheNinth a novel]] and this isn't. In some ways ''The Eagle'' could even be seen as a sequel, as it picks up the storyline some twenty years after the Legion's disappearance.
* HeyItsThatGuy: Oh, look. [[Film/XMenFirstClass Magneto]] was a centurion in his former life, as was [[Series/TheWire Detective McNulty]], [[Series/DoctorWho Mickey Smith]], [[Series/TheWalkingDead The Governor]] and [[Series/GameOfThrones Ser Davos]]. [[Film/QuantumOfSolace Camille]] sure hates Those Crazy Romans.
* WhatCouldHaveBeen: A planned subplot was to reveal that Arianne was actually Etain's half-sister - and Etain was the one who had scarred her face. Etain would have escaped the final battle, returned to Arianne's fort and been killed by her there.