As a ruler in KoH you will be faced with all of the challenges your nation encounters, including but not limited to, defence, war, military strength, religion/piety, economics, development, espionage. territory, diplomacy, and internal power/rebellion. Your decisions will lead to the prosperity or downfall of your society.
There is no formal campaign in KoH, but the regular "Play on Europe" setting will keep you occupied so much that you will hardly notice. When you start a new game you can pick what period of the Middle Ages you'd like to play in, "Early, High, or Late Period". Then you will select one of the kingdoms in the period you'd selected. Early on it will be up to you to decide what kindof nation you will me. Peaceful or warlike? Industrial or Agricultural? Religious or secularist? The list can go on. When you've decided what you will be you continue on and play out your dream, after a couple hours of playing you will feel very connected to the nation that you helped and continue to grow, and lead.
Through minor glitches and downfalls Knights of Honor is truely a worthy title, and is filled with value. I had hesitantly bought it on Steam for 14.99 and was extremely pleased to find the great game that lies under the bargain bin price, I would recommend it to anyone interested in this time period of history or RTS-aficionados.