This month marks the 80th anniversary of what many film buffs regard as THE best romantic adventure movie of all time–“Casablanca,” starring Humphrey Bogart and Ingrid Bergman. It has everything—interesting characters, an exotic location, intrigue, memorable dialogue, and one of the great love songs, “As Time Goes By.” It’s the perfect storm of storytelling and great performances. Surprisingly, it didn’t start out that way.

Filmed and set during World War II, it focuses on an American expatriate (Bogart) who must choose between his love for a woman (Bergman) or helping her and her husband (Paul Henreid), a Czech resistance leader, escape from the occupied city of Casablanca to continue his fight against the Germans. The supporting cast features Claude Rains, Sydney Greenstreet, Peter Lorre, and Dooley Wilson.

The genesis for the movie was a mediocre stage play that was never produced, called “Everybody Comes to Rick’s.” It had very little to do with wartime events, and the finished screenplay didn’t bear much resemblance to it. In fact, the script wasn’t even completed when filming began. Ingrid Bergman complained that she didn’t know which man she was supposed to be in love with at the end—her former lover, Rick Blaine, or her husband, Victor Laszlo. This confusion and uncertainty added some believability to her performance.

“Casablanca” is often cited for featuring a cast that seemed born to play their parts. Many of the supporting players who populated Rick’s Café Americain were actual refugees who had fled Nazi Germany. Would it surprise you to know that the romantic leads weren’t the first choices? A year earlier, Warner Bros. had released a very successful melodrama, “King’s Row,” starring Robert Cummings, Ann Sheridan and Ronald Reagan. When “Casablanca” was approved for production, someone proposed reuniting these three for the roles of Rick, Ilsa, and Victor. Fortunately, calmer heads prevailed and the search continued.

Humphrey Bogart wasn’t initially considered for the leading role, due to the numerous gangster parts he had played. Nobody could picture him as a romantic hero, and even he had doubts that he could pull it off. The film was first offered to George Raft, who turned it down. Bogart practically owed his career to Raft, who kept refusing good parts that eventually came his way. He had passed on “High Sierra” and “The Maltese Falcon,” both of which elevated Bogart’s status. “Casablanca” made him the era’s most popular romantic leading man.

Much has been written about the chemistry between Bogie and Bergman, which made the love story believable. The truth is, they rarely spoke once the cameras stopped rolling. Part of the reason for Bogart’s off-screen aloofness was the constant presence of his wife (not Lauren Bacall, but his then-wife, actress Mayo Methot). She was insanely jealous and was convinced that the co-stars were having an affair. To keep his rocky marriage together, Bogart avoided Bergman between takes, which only added to her insecurity. Asked later about what it was like to work with Bogart, she said “I kissed him, but I didn’t really know him.”

The film gave new life to an old love song, “As Time Goes By.” It was sung onscreen by Dooley Wilson (as Sam), and heard during several key scenes, but it almost didn’t stay in the picture. The film’s composer, Max Steiner, wanted to write his own love theme, but he was overruled. Of note is that Dooley Wilson was a talented singer and drummer, but he couldn’t play the piano.

And that memorable dialogue! “Casablanca” contributed more catchphrases to pop culture than just about any other film, including one that was never spoken:

“We’ll always have Paris.” “Of all the gin joints in all the towns in all the world, she stumbles into mine.” “Round up the usual suspects.” “Louis, I think this could be the beginning of a beautiful friendship.” And the ever-popular “Here’s looking at you, kid.” That line wasn’t in the script, but was ad-libbed by Bogart. For the record, “Play it again, Sam” wasn’t spoken in the film. The actual line is “You played it for her, you can play it for me. If she can take it, I can. Play it!”

The film won several Academy Awards, including Best Picture, Director and Screenplay, but nobody thought it would amount to much initially. The studio released over a hundred films that year, and “Casablanca” was regarded as just another movie, something to take people’s minds off of the war. As they say, timing is everything. It was released while a wartime summit between England and the United States was being held in Casablanca, so the location was in the news. A story about an American expatriate helping our allies fight the Axis of Evil also hit home for a lot of people. The romance element was considered secondary at the time, sort of a counterpoint to the intrigue. It took several years and revivals to turn “Casablanca” into the classic it’s regarded as today.

Break out the popcorn and play it again.