Jerry Lewis and Joan Rivers had a long-standing feud, which started when Rivers started her career in comedy. Lewis did not appreciate female comedians and was particularly critical of Rivers.

This led to a feud between the two, with Lewis even issuing a threat towards Rivers. The exact details of the threat are not known, but Lewis reportedly prevented Rivers from discussing him in the press.

Rivers first met Lewis in 1968.

The two stars met for the first time when Lewis appeared on Rivers’s daytime show That Show with Joan Rivers in 1968.

Although his star and reputation were already on the wane, he was still one of the biggest comedians of his time, having signed record-breaking contracts with both Paramount and ABC in the preceding nine years.

Despite Rivers appearing slightly starstruck during the appearance, the encounter apparently left a bad taste in her mouth, leading her to write in her 1991 autobiography Still Talking of the arrogant way The Nutty Professor star had conducted himself.

“Jerry Lewis, when he was a movie star, came on our dumb little show like the big king, demanding everything,” the comedian said. “He arrived late, full of being Jerry Lewis.

He wanted a bigger dressing room. He wanted champagne. He wanted flowers. Two thirds of the way through the show, he looked at his watch and said, ‘I’ve got to go,’ and walked out.”

Years later, he horrified her during his telethon.

If Lewis’ initial impression on Rivers was bad, it only got worse in the ’80s. In a 2014 interview with Ron Bennington on Sirius XM, Rivers described being appalled at seeing how Lewis interacted with a child during his annual Labor Day telethon benefitting the Muscular Dystrophy Association.

“He was standing there with a child next to him saying, ‘This kid is gonna die.’ And I said, ‘I will never do this telethon again,'” Rivers remembered. “You do not say in front of a little boy who is going to die, ‘This child is going to die.’ Who are you? You unfunny, lucky, stupid [expletive]. So he took umbrage.”

According to Lewis, Rivers subsequently shared some choice words about him with the press—a move that did not go unnoticed.

Lewis admitted to sending a chilling letter.

Lewis brought the incident up years after it happened while recording a SiriusXM Town Hall a The Friars’ Club in June 2014.

“I always feel bad when someone passes away,” he told host Maria Menounos. “Except if it was Joan Rivers.” He went on to say that his nemesis “set Jews back a thousand years” and claimed she went to Israel and uprooted two trees in his name.

“Joan attacked me in the press,” he went on. “All she said was, ‘Jerry Lewis has to be thankful that he has the telethon because it helps his career.’ And then she went on and was even a little more salty. So I wrote her a note that night. I said, ‘Dear Ms. Rivers, we’ve never met, and I’m looking forward to keeping it that way. If you find it necessary to discuss me, my career, or my kids ever again, I promise you I will get somebody from Chicago to beat your [expletive] head off.'”

“P.S. You do know that you’re not allowed to threaten people,” he concluded the note. “So if you go to [the police], show them this letter, they’ll arrest me. But I want you to never forget what it said.”

Rivers hired bodyguards for protection.

“We hired guards, my husband and I,” Rivers told Bennington of her reaction to Lewis’ letter. “It was like a real serious thing.” The outspoken comedian said she then kept uncharacteristically quiet about Lewis because she was confident he “did know people,” joking that she didn’t want her knees broken over Jerry Lewis. “My last words are not going to be, ‘But I was only kidding!'” she added.

She died before the feud could end.

Less than two months after that interview, on Sept. 4, 2014, Rivers died at age 81 due to “therapeutic complications” during a routine endoscopy a week earlier, as reported by CNN. Lewis would have been hosting the same telethon where their feud worsened had he not suddenly parted ways with the Muscular Dystrophy Association three years earlier.

Lewis went on to outlive Rivers by almost three years, dying in 2017 at age 91, but not before commenting, “Joan Rivers and I have not always been the greatest of friends,” according to The National Enquirer. “There are those that we must understand, those that we must forgive—and those that we must hope pass on quickly.”