Must say, i've had an idea for an RTS going round my head for a few years now.
The concept would be that you would be controlling a highly regarded Family inside the World. Being able to build towns and control resources and units like any other normal RTS. However, you would also have Family members to control.
Family members are hero units essentially. They all have different physical builds, attributes and personalities that will help determine how you play the game. They can be married off, sworn to service, killed in battle, born etc. So rather than living out one generation, you are witnessing the Houses rise (and potential fall) from Grace. A few bad decisions could result in a few of your Family members dying and if your entire House is killed, your game is over.
The way the game is made more complicated is that other Houses are controlled by your friends who can be your allies, plot against you or even be at war with you. Your family members personalities will help determine what tactics you can use, some may have a high honour value which would mean they wouldn't break any allegiances. While others could be natural fighters being good leaders for your armies but might not be good fathers resulting in his children being utter shits.
It would be about managing not only your lands and armies but also deciding what happens to your Family Members. You might have a great house built and then suddenly out pops a Joffrey and he suddenly tears shit up. You as the player could try and deal with Joffrey, perhaps by trying to educate him etc. Or you could unleash him to the World as a mad tyrant!