Is Duke Mantee Bogart's most significant role ?
I'd say yes ! Why ? Because he played it 4 times in his career on stage (1935) on screen (1936) on radio (1940) & on TV (1955). He kept returning to this role throughout his career. I am increasingly joining the club that believes this breakthrough role typified & summed up Humphrey Bogart more than any other role.
You visualize him in your mind long before he enters the movie in the 2nd half as he is mentioned repeatedly from the very start of the movie. It's exciting waiting & anticipating Duke Mantee's first entrance in the movie it's worth the wait. A perfect introduction by one of his henchmen Joseph Sawyer as he says " This is Duke Mantee he's the world famous killer & he's hungry ".
Duke Mantee is the role that paved the way eventually turning him into a major star in 1941 in "High Sierra" & "The Maltese Falcon" & "Casablanca". Roy Earle, Sam Spade & Rick Blaine all owe a debt to Duke Mantee in my book. I'm really into his 1930's period more than ever. Bogart did some interesting roles early on & some were excellent & stood out like "Black Legion" in which the movie & Bogart were named best picture & best actor in 1937 by the National Board of Review.
Another notable film he did was "You Can't Get Away With Murder" (1939) a tough gangster prison picture showing Bogart at his baddest with no redeeming good qualities. It's ironic his first feature film was a prison flick "Up The River" (1930) with Spencer Tracy. Tracy was already what he would later become but Bogart wasn't as he was cast in a role like himself.... a rich kid. Too bad Spence & Bogie didn't do more films together. Bogart did many great memorable films but it always gets back to Duke Mantee in The Petrified Forest. Would you agree ??