While out with her sister, Elizabeth sees the man of her dreams and follows him into a jewelry shop. As the shopkeeper addresses the man as "Your Highness," Elizabeth’s heart races, but the man of Elizabeth’s dreams insists he is Sumner Lansdowne, Marquesse of Whitevale, before he departs.

Sumner had reason for the lie. He is, in truth, Prince Leopold’s cousin, to whom he bears an almost identical likeness. Sumner feels a duty to protect his cousin, who has secretly arrived in London to seek the hand of Charlotte, Princess of Wales. To this end, Sumner poses as Prince Leopold at the various Ton balls.

It is at one such ball that Sumner again meets Elizabeth. He finds her irresistible, and Elizabeth’s heart flutters every time she’s near Sumner, though she still believes him to be Prince Leopold. As time progresses, Elizabeth realizes the extent of her feelings and finally admits her love. Sumner has fallen in love as well, but he has sworn to protect Prince Leopold and feels it is his duty to remain faithful to that pledge.

Complications arise when Sumner and Elizabeth find themselves targets of an assassin. Then Elizabeth, still believing Sumner to be Prince Leopold, learns of the prince’s engagement to Princess Charlotte. Sumner struggles between his desire to reveal the truth of his masquerade and his love for Elizabeth. But will he realize that love means more than duty?

How to Propose to a Prince is an excellent romance dealing with secret identities. The powerful plot, exciting action, seductive mystery and intrigue kept me reading well into the night. I love Ms. Caskie’s Regencies, for they are always extremely entertaining and delightful. Even though this is the third book in the series, the story stands on its own as an outstanding novel. How to Propose to a Prince is the perfect romance, an absolutely enthralling read and a definite keeper.