Six cast members played 40 characters.
To receive a "AA" certificate in the UK, allowing audience members under 18, the word "cunt" had to be removed from the scene where Reg blames Brian for allowing the Romans to almost discover the resistance's secret hideout. "Klutz" was overdubbed, though it's quite obvious to the audience what John Cleese is saying.
In the interview section of Monty Python's Flying Circus: Live at Aspen (1998), John Cleese said that because of the massive protests against this movie from all denominations of Christianity, he would joke with Michael Palin, "We've brought them all together for the first time in 2000 years!"
Originally financed by EMI, which backed out because it considered the script blasphemous. The Pythons sued EMI and settled out of court. George Harrison, a huge Monty Python fan, thought it was the last chance to have another Python movie. He created Handmade Films, and "pawned" (his words) his home in London and his office building to raise the £4 million needed. When asked why, he said "Because I want to go see it." Eric Idle joked that it was the highest price ever paid for a cinema ticket.
After the first take of the scene where a nude Brian addresses the crowd from his window, actor/writer/director Terry Jones pulled Graham Chapman aside and said, "I think we can see that you're not Jewish," referring to Chapman being uncircumcised. It was corrected in subsequent takes with a rubber band.
George Harrison: Mr. Papadopolous, owner of "The Mount," who shakes hands with Brian and gives a very Liverpudlian "'ullo." The original recording proved to be unusable, so Michael Palin dubbed it in post-production.
Tom Palin, Michael Palin: at The Mount, with Mr. Papadopolous. Tom was the only Python child who wanted to be in the film. Michael Palin later joked that his son would be able to tell people he appeared in a scene with the Pythons and one of The Beatles.