- Acting for Two: William Hartnell plays both the Doctor and the Abbot of Amboise.
- Alan Smithee: This story was originally written by John Lucarotti, but script editor Donald Tosh rewrote almost the whole story. Lucarotti demanded his name be taken off the credits, but since the episodes are missing, it's unknown whether his request was granted.
- Creator Backlash: John Lucarotti was so unhappy with the rewrites made by Donald Tosh that he took his name off it. (Due to the fact that none of the episodes survive, there is some debate about whether or not he was actually credited; Tosh claims the episodes had no writing credit, but it seems he may have been credited on Episode 4 at least as Tosh received co-writer's credit on that.)
- Creator's Favourite Episode: Peter Purves named this as his favourite story.
- First Appearance: Of Dodo.
- Missing Episode: One of only three stories (the others being "Marco Polo" and "Mission to the Unknown") for which not a single frame of footage survives. No telesnaps, no clips, no photos other than publicity photos. Even the novelisation is In Name Only because it's based on earlier drafts of the script. There's not even a single picture of Hartnell as the Abbot of Amboise, so we have no idea what his costume looked like. Reconstructions of the serial consequently have to photoshop stills from other serials into a loose approximation of what the footage might have looked like.
- What Could Have Been:
- Anne Chaplet was considered to become a main companion. As with Katarina, it was decided that her origins made her less than ideal for viewer identification.
- Ian and Barbara were supposed to have a cameo at the end of the story and watch the TARDIS just as it dematerializes.
- Working Title: The War of God.
Trivia / Doctor Who S3 E5 "The Massacre"