I would agree with the sanctuary thing. Since both sides are fighting for the right to rule, and one would have snatched up the capital as quickly as possible, perhaps one or more of the largest cities in the kingdom. Not the capital if it's been 'snatched' since whoever's there would just hold out there as long as possible, but maybe a large city known for trade of all kind. You know, stores, gambling, red light, etc. A place where everyone can go, and have a good time. Somewhere between both sides, where nobody has the advantage.