Ideas
 

Im trying to think of ideas for stuff to write lyrics about. My band plays basically some thrash with a little tremolo picking and melody here and there. Its kinda hard to explain (im not exactly clear on the exact meaning of thrash). Anyways, anyone have any ideas on stuff to write lyrics about? im thinking about writing some on a historical war (that actually happened)

I like that idea a lot and I think the ideais twofold. You'd be writing a song that has a definite storyline to it already, but others can learn from the lyric even if it's the smallest thing. That might spark someone's interest. I'm not sure about the metal field, but Neil Young did some songs that had historical flavor.
Another idea you might use is to take an old song and make it in your own style. Metalica did it with "Whiskey In The Jar" and a few others did "House of the Rising Sun," Zeppelin did "When the Levee Breaks." They're all songs from around the early 1900's or before. That might give you some ideas.

Just make sure when you write about a historical subject that your details are accurate. Someone who knows more about the subject will certainly give you grief over it if you don't. ;)

And you might do a "search" in the P/L section for more ideas. This subject pops up every once in awhile.

I once wrote a lyric about a historical war (about Odovakar, the Germanic tribe leader who kicked the last Roman emperor's butt, end 5th C).

Just look up some facts and pay attention to details, like nicknames for an army or heroic anecdotes. Those are things to elaborate on in your text, gives some colour too.