The eastern isles and cities of the Hold are dominated by a single theocracy. The remainder is under various warlords’ rule. There are tons of wave-men (ronin) running around the countryside putting out fires (and most often starting a few more), some out of ideology and most as mercenaries. The Sea Hold is 1) a good nautical base on a mainland coast 2) with enough political turmoil that currently remains stable so long as you don’t wander into the wrong neighborhood wearing the wrong “colors” 3) but enough political tension that everything could fall apart with the right catalyst. In the meantime, everyone is trying to live their lives, only surrounded by what is effectively terrorism and the occasional monster / humanoid incursion. It’d be like living in Palestine in a more stable decade with the occasional raiding party coming out of a nearby jungle. The Holds were built on slavery but there have been some major slave revolts in their recent history (which didn’t eliminate slavery so much as change up who was the slave and who was the slave-master).
Also Keoland is directly to the north and would provide a “foil” in the shape of a Good kingdom (i.e. an Israel equivalent) for those who wish to have sympathy for another nation’s political cause. Party members could easily be from either there or local because the Sea Hold people are currently more worried about civil war than foreign invasions at this stage (and likewise Keoland is glad that they’re self-occupied).