I had a new game where nobody declared war, but I went and made harvest princess declare war (on a recruit all the princess if possible run), and as soon as I did everyone declared war on everyone. Be careful what you wish for. It seems like if anyone declares war, it drastically boosts the chances that others will declare war, and as soon as I resolved all the wars, it has been peaceful ever since. Skeleton princess, and the cat princess are warmongers, FYI, mouse princess cannot be declared against, and harvest princess and bunny princess are pacifist, and will very likely not get declared against unless you force it, or one of the warmongers starts to conquer the world. Slime Princess and Moth Princess WILL fall if you leave things to fate, and in the south if war starts to be declared, everyone will declare war on the goblins, for whatever reason, if you get a bad roll, and want to do something with the goblins but are too low level and lack points with the south, the goblins and moths can get wiped out before you have a chance to do anything. Easiest princess to get to rule the world is probably skeleton, or human. If you keep all the realms peaceful, they will all get super rich.