One thing that occurred to me while watching Episode I just now - why do the Gungans have a 'grand army'? Who do they fight? Who have they fought? Why maintain an army unless you're at war often, or are fearful of someone? Clearly they shouldn't fear the Naboo, who are pacifists and only employ security volunteers. There's no evidence that the Gungans have conflict or even contact with beings off-planet. So what gives? Are there other species on Naboo that the Gungans are at odds with? It's clear from what Jar Jar says that the Gungans have somewhat of a warrior culture ("Gungans no dying without a fight, wesa warriors"), yet I can't think of one logical reason how that could have evolved.

Unless... maybe the Naboo weren't always peaceful and used to have some conflicts with them? Still, I don't think that could explain all.

Anyone have any ideas?

EDIT: Ok, nix that idea: "our two great societies have always lived in peace". Hmm.