In the early years of Henry VIII's reign, the title was awarded to minions of the King, court companions who spent time with him in the Privy chamber. These were the sons of noblemen or important members of the gentry. In time they came to act as virtual personal secretaries to the King, carrying out a variety of administrative tasks within his private rooms. The position was an especially prized one, as it allowed one unobstructed access to the King's attention. David Starkey writes: "The Groom of the Stool had (to our eyes) the most menial tasks; his standing, though, was the highest ... Clearly then, the royal body service must have been seen as entirely honorable, without a trace of the demeaning or the humiliating." Further, "the mere word of the Gentleman of the Privy Chamber was sufficient evidence in itself of the king's will," and the Groom of the Stool bore "the indefinable charisma of the monarchy."
From: http://en.wikipedia.org/wiki/Groom_of_the_Stool
