"Night on Bald Mountain" by Mussorgsky via Rimsky-Korsakov is quite a stirring piece of music.
If you can find it, you might like the battle music from the 1962 film "Taras Bulba".
I liked the music from the 1965 film "Battle of the Bulge", especially the German "Panzerlied" (just about anything seems more martial when you sing it in German).
The old "Victory at Sea" TV series had scads of music to complement its combat footage. You can find some samples here:
http://victoryatseaonline.com/victory_music.html
Edit: The "Conan the Barbarian" soundtrack also has some nice "barbaric" battle music.