Ghirlandaio has a very demure picture of St. Barbara holding her tower. Then you notice she’s standing on a corpse.
Yeah, she’s doing her military saint gig.
Legend has it that God smote down her pagan father with lightning for imprisoning and martyring her. Thus her work as patron of artillerymen, et al. Later versions of the legend often reinterpret pagan as paynim, making Barbara’s dad look Muslim by giving him a Persian-looking helmet. Ghirlandaio uses such an Eastern helmet here, also.
Another popular one was depicting her holding a chalice with the Host suspended over it. Much more peaceful.
But be sure to check out this huge wallpainting of Stories of St. Barbara by Lorenzo Lotto. Holy cow, look at that beautiful marketplace! You could go there tomorrow and recognize people! Also, it is not everyday, outside of a comic book, where you see scenes of the watching cloud of witnesses shooting out of someone’s hand.
UPDATE: However, she’s not just for pre-moderns and Catholics. Behold, the American military honor society, the Order of Saint Barbara, which has its own medallion and everything. Also, there’s the Order of Saint Maurice for infantry guys, the Order of Saint Martin for quartermasters, the Saint George Award for tankers and the Order of Saint Joan d’Arc for their spouses…. Awesome stuff I’d never heard about!
Also, loukoumades (honey puffs – you’ve probably had them at Greek restaurants) are served on her feastday in Greece by the artillery guys, under the theory that they look like cannonballs.