In the new King's Quest series universe ([[Reboot Canon]]), Graham states in that his family comes from a long line of nobles, and one very clever dentist (equating 'knights' to nobles). His family has always protected crowns.
Graham belongs to a long line of logically-minded nobles. And one very clever dentist. His father was a knight, and his grandfather was a knight,, it was his great grandfather who was a dentist, but his father was a knight. He came from a long line of protecting crowns.