Battle of Warsaw 1920 is a fantastic Polish film about the Polish war after the completion of WWI left the country independent. The film looks and sounds fantastic, and the main characters create an involving love story as the backdrop to the war. The lead actress is exceptional, she goes from cabaret singer to nurse to manning a machine gun over the course of the film, and makes it completely believable.
The only problem with the film is that to Americans who know nothing of this era, it is quite confusing. It's hard to tell who is Polish and who is Russian if you are not paying attention. But I do strongly recommend this film if you get a chance to see it. Apparently it's the first Polish film shot in 3D, although I saw it in 2D, the battle scenes probably look stunning with the added depth.