The royals are coming, the royals are coming! In this case, the grandson of the Queen of England, along with his wife, who took a fairytale leap from commoner to duchess by marrying him. (Just imagine, Kate Middleton a duchess while Margaret Thatcher was only made a countess.) And once again Americans who have forgotten the American Revolution are telling us to bow and curtsy before them, and address them as "Your Royal Highness," and stand when William enters the room.
So one more time: Americans don’t bow or curtsy to foreign monarchs. (If you don't believe me, ask Miss Manners, repeatedly.)
This is a republic. We do not recognize distinctions among individuals based on class or birth. We are not subjects of the queen of the England, the emperor of Japan, the king of Swaziland, or the king of Saudi Arabia. Therefore we don’t bow or curtsy to foreign heads of state.
Prince William's claim to such deference is that he is a 24th-generation descendant of William the Conqueror, who invaded England and subjugated its inhabitants. In Common Sense, one of the founding documents of the American Revolution, Thomas Paine commented on that claim:
Could we take off the dark covering of antiquity, and trace them to their first rise, that we should find the first [king] nothing better than the principal ruffian of some restless gang, whose savage manners or pre-eminence in subtility obtained him the title of chief among plunderers; and who by increasing in power, and extending his depredations, over-awed the quiet and defenceless to purchase their safety by frequent contributions....
England, since the conquest, hath known some few good monarchs, but groaned beneath a much larger number of bad ones; yet no man in his senses can say that their claim under William the Conqueror is a very honorable one. A French bastard landing with an armed banditti, and establishing himself king of England against the consent of the natives, is in plain terms a very paltry rascally original.—It certainly hath no divinity in it.
Citizens of the American republic don't bow to monarchs, or their grandsons.