Oliver Reed sustained a head injury close to the eye when his character was being attacked by peasants with pitchforks.
This was one of two appearances for Oliver Reed. The other being "King of the Beggars." In which he sustained a concussion.
Roger Moore, the star of this show, directed this episode. It also marked his directorial debut and the first of nine shows he directed from 1964 and 1968.
Tommy Duggan, who plays the title character's father, and Hal Galill, who is a tough thug, both appeared in Superman II within the same Diner scene: the first ran it, the latter a customer.
Oliver Reed's American gangster voice can be heard in different variations through his career, like when he uses them as imitations, mostly for joking around, like in The System. He was a master of imitating various accents.