Heath Ledger, Shannyn Sossamon, Mark Addy, and Leagh Conwell all previously appeared together in Corazón de caballero (2001). Both movies written and directed by Brian Helgeland.
Originally scheduled for January 17, 2002, the film's release date was postponed when the visual effects had to be redone because they were thought to be unintentionally funny. According to a anonymous source close to the production quoted by Variety magazine, the special effects depicting sins exiting the human body after death looked like "calamari".
According to Brian Helgeland, Peter Weller did extensive research for his role by studying old religious rituals and histrionics.
Leagh Conwell also portrayed Heath Ledger's younger self in A Knight's Tale.
Brian Helgeland also wrote and directed A Knight's Tale which starred the three main leads of The Order.