The title is translated as "The Legend of King Arthur's Sword" in Thai.
Ferdinand Kingsley, son of actor Ben Kingsley, played Sir Ben Kingsley's character in flashbacks as a young man in Britannia (at 13:27).
Romulus' throne was built specifically so that the feet of 15-year-old Thomas Sangster would not touch the floor when he sat in it to reinforce the perception of a small child being dwarfed by events going on about him.
Shots were removed from the U.S. version of the film so it would receive a family (PG-13) rating. (At 24:14, a shot of the crow flying down, picking up Wulfila's finger, and flying out of the room, as well as a shot at 42:06 of Wulfila's face hitting an axe blade, among other shots.)
The statue of Gaius Julius Caesar (at 37:00) was not the primary statue used in Tunisia; rather, it was a special effects statue with a large gaping hole in its back and which was intended to be rigged to blow up. When production moved from Tunisia to Slovakia the primary statue was lost.
Director Doug Lefler says that the story idea started as a film concept at DDLC, then Dino De Laurentiis brought Valerio Manfredi on as a historical consultant and he fell in love with the idea. When progress at DDLC on the film stopped, Valerio Manfredi went off and made a novel of the idea which became successful in Europe and helped get the film going again.
Director Doug Lefler managed to get all of the family of Thomas Sangster in the film (uncredited). At 01:01:10 Thomas' mother Anastasia is shown hugging Kustennin, commander of the Ninth Legion, and again at 01:09:40 as Ygraine's mother. At 01:03:25 Thomas' younger sister Ava is shown as the first Celtic girl in the scene where Ambrosinus explains the heritage of Caesar's sword. At 01:10:48 in the background by Kunstennin, as the blacksmith begins stating his view of Romulus living among them, is Thomas' father Mark.