Kevin Smith, who played Valdemar, died shortly after finishing this film. The film is dedicated to his memory.
Alice Hargreaves (Emily Lloyd) was, as Alice Liddell, the little girl who inspired Lewis Carroll to write Alice in Wonderland and Alice Through the Looking Glass.
In the early novels, the chief villain was King John "Lackland" Plantagenet, who ruled England 1199-1216. It is not clear why this was changed to the Roman Emperor Nero for the film.