> The 50 days, obviously during a long war they may be enlisted longer, would be as and when their lord called them up. And so a Knight would only receive pay for the days they were called up, the rest of the year they live on the taxes from their small fief and whatever other activities they took part in. Many tried to marry rich heiresses for the wealth. And with the Knighting I BELIEVE (Though I may, and am happy to, be wrong) was carried out by anyone who carried a title higher than a knight's, so someone who had land to give as a fief.   

Cool. I like that. 
Here's another idea: castles can be owned by the Duke, Counts and Burgraves, larger towns can be owned by them as well but also by Lords while knights can only manage villages and the surrounding land that belongs to the village. Patricians and Edlers could be awarded villages to manage as well, though they will mostly be landless nobility. They can profit from trade, own bakeries, breweries, inns, etc.


Technically, knights owning whole villages is a bit ahistorical, correct? But I simply do not know a better way to divide fiefs in accordance to titles. If you guys have better ideas I'm listening.