One of the coolest old Sci-Fi strategy games from back in the day.  Emperor of the Fading Suns.

It's basically a turn based strategy game where each side starts with one planet, as a noble family, and works to gain the emperors seat.  There's also the Church with their own planet, etc, and other stuff.  If you don't know the game check out the wikki page.

http://en.wikipedia.org/wiki/Emperor_of_the_fading_suns

Super old game.