There's a place for everyone and everyone has a place in the medieval society of The Once and Future King. For the most part, the upper classes didn't mix with the lower (unless it was to use them as sword fodder during war, or to boss them around). Even Arthur, who has respect for lower-class characters such as Hob and Robin Wood, doesn't really mix and mingle with the riff-raff once he's king.
There are a couple of exceptions. Merlyn seems to be more comfortable with the lower classes than many others, and Sir Ector seems right at home with his employees at his Castle of the Forest Sauvage. For the most part, the upper and lower classes are distinguished by their clothing, where they live, the jobs they do, and their speech: White uses different accents to show whether someone is aristocratic or a "villein," or peasant. (See "Character Clues" for more on this.)
Questions About Society and Class
What is the effect of using different speech and dialects to characterize characters of the lower classes?
How is Sir Ector more comfortable with his servants and serfs than some of the other upper-class characters? In what ways is he more like them than like the other nobles?
What are the different ways that having money and being of the upper class protects a person from some of the harsh realities of the medieval setting?
Chew on This
Arthur can never truly have empathy for the serfs and villeins because he was raised in an aristocratic household.
Part of what White is trying to show in his novels is the arbitrary nature of social class divisions.