Who is Sir Humphrey Marlow from The Prince and the Pauper and what is their importance?

Humphrey Marlow is the Prince Edward's whipping boy. He takes beatings for the prince when the prince fails to perform well at his studies. Humphrey later becomes Tom's confidant. Thinking that he is actually helping the prince to regain his senses, Humphrey is a major source of information about the workings of the court.