In 1944, Dean Martin met a young Jerry Lewis at the Glass Hat Club at the Belmont Plaza Hotel in New York City, where both men were performing.

[2] The highlights of their act included Lewis interrupting and heckling Martin while he was trying to sing, which ultimately led to the two of them chasing each other around the stage.

Lewis hired young comedy writers Norman Lear and Ed Simmons to improve their act.

[4] Also in 1949, Martin and Lewis were signed by Paramount Pictures producer Hal Wallis as comedy relief for the film My Friend Irma.

Martin was thrilled to be out of New York City, a place he had developed a lifelong discomfort with, and he also had a dislike of tall buildings.

He did not like climbing multiple flights of stairs in tall buildings or taking the elevator if he needed to go to a high floor.

Their Comedy Hour shows consisted of musical song and dance from their nightclub act or movies, with Dick Stabile's big band, sketch comedy with slapstick or satires of current films and TV shows, Martin's solo songs, and Lewis's solo pantomimes, physical numbers or conducting the orchestra.

The tour was so successful, audience members would not leave their seats, so Martin and Lewis began doing "free shows" afterwards on fire escapes or out their dressing room windows, jamming the streets with adoring fans hoping to catch a prize – a hat, a shoe, maybe an autograph.

During the shooting of what was to be their final film together, Hollywood or Bust, during the spring and early summer of 1956, their mutual animosity reached the point where, as Lewis later related, "I wouldn't tell Dean what I thought of him, so [director] Frank Tashlin took all the flack.

"[7] After the film completed principal photography on June 19, their professional breakup was widely reported in the press, although they subsequently fulfilled a contractual obligation with a farewell engagement at the Copacabana Club, which ended on July 25, 1956, ten years to the day from their first official teaming in Atlantic City.

Martin's career arguably reached new heights after the team split up, as a recording artist for the Capitol and Reprise labels, as a movie actor both on his own (Rio Bravo, The Young Lions, the Matt Helm series) and as a member of the Rat Pack (Ocean's 11, Sergeants 3, Robin and the 7 Hoods), and with his own hugely successful 1965–1974 television variety series, The Dean Martin Show.

He also continued with his philanthropic work, which had begun while still partnered with Martin, hosting telethons for muscular dystrophy research until 2010.

In 1958, Lewis was the guest on an episode of NBC's The Eddie Fisher Show and was bantering with the host when Martin emerged from behind the curtain and said, "Don't sing.

After the applause died down, Fisher sang a few bars of Crosby's theme song "Where the Blue of the Night (Meets the Gold of the Day)" and Lewis crooned the title of Martin's then-current hit "Return to Me".

The two men reconciled in September 1976, after Frank Sinatra orchestrated a surprise appearance by Martin on Lewis's annual Labor Day telethon for the Muscular Dystrophy Association, saying only "I have a friend who loves what you do every year."

Lewis presented him with a birthday cake, thanked him for all the years he gave joy to the world, and finally joked, "Why we broke up, I'll never know.

Despite their animosity after the split, Lewis published an affectionate memoir of his partnership with Martin called Dean & Me: A Love Story in 2005.

Directed by John Gray and starring Jeremy Northam as Martin and Sean Hayes as Lewis, the film depicts the years from 1946 to 1956, spanning the entirety of their partnership from the beginning until the end.

In 2016, a tribute show called Dean and Jerry: What Might Have Been, starring Derek Marshall as Martin and Nicholas Arnold as Lewis, started touring North America.