Henry Winkler played a key role in helping Sylvester Stallone make the originalRocky. Written by Stallone with the actor also starring as the titular boxer, the iconic sports movie was released in theaters to great success in 1976. It would simultaneously spawn a highly successful franchise while launching Stallone’s career as a Hollywood star.

The story of how theBarryactor came to get involved with the creation of the iconic boxing movie was revealed byHenry Winkleron Wednesday night’s edition ofThe Tonight Show. At the time, Winkler was starring as the Fonz onHappy Dayswhen his friend, a then-unknownSylvester Stallone, asked him to pass along a script he wrote to the bosses at ABC. The network actually did buy the script, though Winkler had to essentially beg to get it back after they wanted to rewrite it with a new screenwriter.

“[ABC] liked the script, so I sold them the script,” Winkler recalled. “And I called Sly and said, ‘We sold the script!’ Then ABC called and said, ‘We want to change the writer.’ I then called Sly and said, ‘We sold the script, [but] they want a new writer.’ And he said, ‘Henry, don’t let them do this to me!’ I said, ‘All right. Absolutely.’ I went back to ABC. I said, ‘I know this is strange. Here’s the money. I need the script back.’ They said, ‘We don’t do that.’ I said, ‘This time, I am begging you. Please.’ I got the script back. I gave it to Sly and said ‘It’s all yours.’ And a year later, it turned out to beRocky.”

Following rejections from other studios, United Artists was the production company that picked upRocky. Stallone also had to convince the producers to let him play the lead role as well, otherwise the deal would have been off the table. They ultimately agreed, and the rest is cinematic history. On a budget of less than $1 million,Rockywould pull in $225 million at the box office, which equates to more than $1 billion in today’s money. Because Stallone was so perfect for the role, it seems unlikely it would have been as big of a success if someone else played Rocky.

These days,Stallone is still heavily ingrained in the Rocky franchise. He has been working hard on releasing a new director’s cut ofRocky IV, one of the most popular installments of the franchise. The new cut, dubbedRocky vs. Drago - The Ultimate Director’s Cut, will include new footage which Stallone says more aligns with his own creative vision of the movie. This also means getting rid of Paulie’s robot, one of the more controversial aspects of the story.

Meanwhile, the franchise continues with theCreedspinoffs as well. Michael B. Jordan is currently preparing to make his directorial debut withCreed IIthat will also see him returning as Adonis Creed. Stallone will not be back as Rocky in that sequel, though he has recently revealed he has another sequel idea in mind that will put the Italian Stallion back in the main role. He also wants to make a prequel series set before theoriginal Rocky.