To expand on empires a bit since that wasn't the best explanation...
When you start a new game you get a few historical scenarios to pick from (or possibly have to unlock them) and a fictional one that randomizes everything. Beyond the initial lay out of the the territory ownership however from there on it's anything goes and you are free to chose how you want to go forward. 7 and XL don't have a map feature and you instead just select pre prepared battles.
You have to manage your officers leveling and gearing them up, recruiting more, as well as keep their troop level up which basically acts as HP for the AI. During the battle phase you can either chose to attack neighboring territories, defend if you are being attacked or wait and do nothing. 6 had a playing as an officer rather than a ruler option but I don't remember it much because DW6's combat was somewhat less than special...
Overall it's a really fun game and dispute the somewhat simple system the difficulty becomes intense at the high levels. Knowing which of combos to use and how best to approach a mob of enemies is extremely important because they can mess you up quick if you let yourself get hit. In samurai warriors 2 empires for example I would get almost 1 shotted with a capped officer including an ability that refilled your health bar once a battle when it was emptied (so kinda like RR). Even the peon enemies would take like 1/8 my hp XD