Queen Elizabeth II was actor Rex Harrison’s “fair lady” Tuesday as she proclaimed him a knight in a ceremony at Buckingham Palace. He will be formally known as Sir Reginald. The 81-year-old actor, who starred as Henry Higgins in “My Fair Lady,” was awarded the knighthood in recognition of his services to the arts. “I think they rather like to leave awarding honors until you get to a certain age,” he said. “It was a marvelous moment kneeling there and getting tapped on each shoulder.” Knights must kneel before the queen who taps them on both shoulders with a sword as part of the ceremony.