I conquered Sinai on crusade, and I decided to give it to the Knights Templar as a reward for helping me win. I thought this would make them my vassal, but it doesn't. It doesn't make them cheaper to hire or anything. I have the option to request vassalization, but they won't accept.
So, what's the point of doing it? Besides roleplay, of course.
So, what's the point of doing it? Besides roleplay, of course.