Bakster
I have not seen 55 Days in Peking,
If memory serves, it's out in the You Tube wilds, if needed. (Watched "Away All Boats" o YT over the w/e--still a cool story.)
Tale is a fictionalized one of the Boxer Rebellion incident, where the International Cantonment was surrounded and beseiged in 1900.
It was a mix of Embassies and Legations, with family in tow, and was considered a bit of a plum diplomatic assignment. The various nations had supporting military forces, which would have been armed with a great plethora of arms.
The Brits would have had Metford-Lee, the French, Lebel, the US Marines 6mm Lee, and so on. The movie manages to engage in characterization without extensive exposition, so, it's natural and fluid. The pace starts a bit slow, but picks up. It does not hold that accelerated pace, but lets you breathe and be part of the story.
David Niven pulls off a masterful performance, as does Charlton.