Kirk Douglas used his horse to threaten “Spartacus” director Stanley Kubrick when they were shooting the iconic “I am Spartacus” scene from the 1960 film.

During Thursday’s episode of the Turner Classic Movies podcast “The Plot Thickens,” host Ben Mankiewicz recalled how Kirk was upset with Kubrick for ignoring his memo about the famous line from Dalton Trumbo’s script.

Kirk wanted to keep the quote, Mankiewicz said, while Kubrick removed it from the script without consulting the film’s lead star.

So, Kirk allegedly “trotted” over to Kubrick on a “big brown horse” that got “inches away from Stanley’s face,” and told the director: “When I send you a memo about shooting a scene, I at least expect an answer. I sent you that note about the ‘I am Spartacus’ scene, and you haven’t even bothered to respond.”

Kubrick allegedly replied, “That’s because I don’t wanna do it – it’s a stupid idea.”

Kirk, in response, “pushed the horse right up against” Kubrick, according to Mankiewicz.

“Listen, you little pr–k. This may be a stupid idea, but we’re gonna try it,” Kirk allegedly told Kubrick. “If it doesn’t work, we’ll cut it out, but we’re gonna shoot it.”

Kubrick ultimately agreed to Kirk’s demands, and the next day, they filmed what Mankiewicz called “the most famous scene in the movie.”

Earlier in the podcast, Mankiewicz recalled how Kirk brought Kubrick onto the project after the actor “had grown frustrated” with original director Anthony Mann.

Mann, according to Mankiewicz, “was encouraging the actors to improvise their lines,” which caused production to “fall way behind schedule.”

Thus, Kirk took matters into his own hands and got then-31-year-old Kubrick, whom he previously worked with on 1957’s “Path of Glory,” to join the “Spartacus” team.

“There were two things I knew about Stanley,” Kirk, voiced by his son, Michael, on the podcast, said. “First, even though he was only 30, he had the talent and self-confidence to step in and take over a picture of this size.”

“Second,” Kirk added, “his self-confidence often bordered on arrogance, a quality that could be a help or a hindrance when dealing with hard-to-rein in actors such as [Laurence] Olivier, [Charles] Laughton, and [Peter] Ustinov.”

Despite the behind-the-scenes issues, “Spartacus” was a massive success, grossing over $60 million worldwide on a $12 million budget, and winning four Oscars out of six nominations

The film is regarded as one of the greatest war movies of all time.

Kubrick died in 1999, at age 70. Kirk passed away two decades later, in 2020, at age 103.