One of the 4 Catholic kingdoms, The Kingdom of Iowa is usually either the most powerful or second most powerful of them, after the Kingdom of Comancheria. It is one of two Grangelander Kingdoms, along with the Kingdom of Platte.
Iowa has an easily defensible geographic position. It is bordered by The Papacy and the Duchy of Boonslick to the south, the Kingdom of Platte and the Duchy of Kansas to the west, the Kingdom of Lakotah and the tribe of Freeborn to the north, neo-norse and rust cultist tribes to the northeast, and the Duchy of the Quad Cities and the Duchy of Forgottonia to its east, sharing the Mississippi river with Iowa. The kingdom has a compact form, making it a difficult target for raiders.
Iowa's strong defensive position and nearby allies, in particular the pope, make Iowa a true stronghold of Catholicism. However, Iowa is threatened by its heathen neighbors to the north and east, who tend to launch prepared invasions against it.
AI Iowa is very defensive and, more importantly, won't waste its energies in useless wars against its catholic neighbours, thus the region is stable and able to stand against threats like Lakotah. Interesting is the relation with Platte. It's not rare that the two kingdoms will form a deadly alliance, usually this means the downfall of Lakotah, or at least the fact that between the Pope and the other religions there are 10k men defending him.
A canny (and lucky) player can place a Greysnow on Platte's throne in the early game, bringing Iowa much of the way towards forming either the cultural Grangelander Empire
A purported history of Iowa is related in the primer, 'Our Liberties We Prize And Our Rights We Will Maintain.'
The Iowan king Daniel is rumored to have secretly gotten married in California and adopted a child, but there is no way to prove this ever happened.