My question is two-fold.

Does anyone know how Nobilty works? I mean a list of titles and the expected duties

Something along the lines of
King/Queen- Rules the land.

I have some idea of some of the name of some of the titles. Never really sure exactly what their jobs entail. I know, I know alot of people will just say *Make up your own titles and jobs.* I just want some idea as how it mostly works. English-type kingdoms work, but I would like other regions titles and nobilties so I can add flavor to my worlds.

My second question is, does anyone know the logic of building castles and supporting towns? I have this idea for a Barony. It's located on land mass connected to the main land by a brigde. Its function is to server as a King's Port. A place the king uses to get materials and supplies quicker than his subjects. I just don't know how it would work out. The Island has two major towns the port, and the Baron's castle. One of the town is located by the Castle, I am just not sure if the Town would be INSIDE the castle walls, or outside. Which would be the better postion for the town. Also, this ties in with the first question, as I am not sure if a Baron would have such an important land holding for the king. Do you think I should make the Baron a Duke instead?