I have not seen many Martial Art movies in my time. However here are 2 of the movies that I have seen and recommend taking a look at.
When Taekwondo Strikes is a movie from 1973 that tells the story of a group of Korean rebels who use their art of Taekwondo to cause the Japanese oppressors a lot of trouble in the early 1940s. They are basically Taekwondo freedom fighters.
This is a fictional movie; however, the film can give you a good feel of what it would have been like in Korea under Japanese colonial rule.
When Taekwondo Strikes (1973):
Hapkido came out a year before When Taekwondo Strikes and has many of the same cast members, playing similar roles. The majority of this story is set in China and the main protagonists are Chinese. The movie starts off with our young protagonists training as Hapkido students in 1934, under the guidance of their wise Korean master. Their teacher believes that his students are now ready to open their own school. As Korea was under Japanese rule, he asked his students to go back to China in hopes of spreading the art of Hapkido in an environment that would accept it.
The protagonists establish a Hapkido school in a town back in China. They quickly realised that life in China was no longer very different to life in Korea as the Japanese now ruled much of the ancient society. More immediately however, a certain "Black Bare" Japanese Martial Arts school threatens the existence of the newly established Hapkido school, the local Kung Fu schools, and the safety of the local population...
I like both movies. However if I were to select a superior film, I would choose Hapkido. Hapkido has a slightly more compelling and memorable storyline with exigent fight choreography, even though it might be unrealistic at times. I think that When Taekwondo Strikes relied a little bit too heavily on the fight scenes, where as Hapkido had a nice balance of an interesting story, well defined characters, Martial Arts action and philosophical teachings. This is why Hapkido was the film that I came back to re-watch. All of this is just my opinion. Both films are great and both will provide you with a good understanding of the struggles people in China and Korea went through during the first half of the 20th century, whilst hopefully providing you with an adequate fix of Martial Arts action.
Thank you for reading. If you decide to check out ether of these films, happy viewing!