I've been a Laurel & Hardy fan since I was old enough to first watch TV. Being relatively ancient, when I was little, all TV was B&W and L&H were staples of kids programming. Stan Laurel, who wrote most of their dialog and dreamed up most of their business is, IMHO, a comic master against whom all others must be judged.
Like several other of their full-length features, this is a comic adaptation of an operetta. It's easily the best of the bunch, an opinion Stan reportedly shared. The original, "Fra Diavolo" by Auber is a generally forgettable and somewhat stuffy bit of fluff that's rarely performed. With the addition of Stan and Ollie's comic business, it's transformed into a work of sheer genius.
The most recognizable and catchy tune from the operetta, the "Romanze", or Diablo's theme, plays a central role in the funniest scenes of the entire show. The "kneesie-earie-nosie" and "finger wiggle" scenes are classics, beloved of L&H fans. Stan's progressive inebriation at a critical point is the locus for another set of riotous bits.
Highly recommended!