So I've been reading the Byzantine Art of War, and one of the things that stuck in my head was the so called "Border Lords" in the 7th-9th centuries. These were the Dux, Komes, and other men who watched the border between the Byzantine Empire and the Caliphate in Anatolia. This was a conflict defined by raids, quick guerrilla strikes, and the occasional big (that is to say, approximately 5.000 men) push either way to take a city or a fortress. This conflict inspired many epic poems, the most famous of them called "The Two Blooded Border Lord". Political actions were also bursting at the seems, with the heads of both states swaying between truce and war, and on the local level, bribing or assassinating rival commanders on either side of the border.
What I was looking for is anyone who is interested in roleplaying the sort of conflicts. I'm undecided whether this should be a system or a freeform game, though if it were a system, I'd be using the Pathfinder rules (that being the only system I'm familiar with). It won't be set in the historical period, but the situation will be the same.