In the early ’70s, Sylvester Stallone was an actor struggling to make an impact in Hollywood. Then one night, everything changed. Stallone saw journeyman battler Chuck Wepner’s fight against Muhammad Ali and take the champ to within 19 seconds of going the full distance.

Wepner’s heroics inspired Stallone. He knocked out a screenplay in three days and stuck to his guns, refusing to sell it unless he could also play the lead role. The rest is history. “Rocky” was a smash hit and received nine Oscar nominations, including Best Actor and Best Original Screenplay for Stallone, and won Best Picture and Best Director for John G. Avildsen.

After the roaring success of “Rocky,” it was pretty much Stallone’s franchise to do with what he wanted. He wrote five sequels and directed four of them, the sequence broken only by Avildsen returning to helm the dreary “Rocky V.”

The trajectory of the “Rocky” franchise is pretty wild. After “Rocky II” made Balboa heavyweight champion, the series grew increasingly cartoonish in the ’80s, much lampooned for its over-reliance on training montages. The dismal “Rocky V” still made good box office but felt like the antithesis of the previous installments, seemingly spelling the end of the franchise.

Then in 2006, after a run of poor movies, Stallone brought his beloved character back again in “Rocky Balboa,” a return to the character-based drama of the original after the more bombastic entries.

Stallone and Rocky still weren’t quite done. “Creed” came along in 2013 and Stallone reprised the role as an aging Balboa training Apollo Creed’s son Adonis (Michael B. Jordan). In a nice touch of symmetry, Stallone received an Oscar nomination for his performance. He returned once again in “Creed II,” before dropping out of the series altogether before “Creed III.”

slashfilm