To avert war between their countries an official marriage is arranged between Crown Prince Boris of Moraine and Princess Flavia of Norvia. Prince Karl of Norvia sees in the alliance an opportunity to gain control of both kingdoms but upon visiting Boris finds him unyielding and independent. Flavia, shedding her stately dignity in the palace garden, is accosted by the flirtatious Boris, who believes her to be the princess' cousin; and falling in love, he realizes that he cannot go through with the planned marriage. Karl plots to have Boris abdicate, and at the pleas of the minister, Boris refuses to fight the regent and is disgraced. To assure his safety, Princess Flavia agrees to marry the imbecile prince, Michael; Boris is secretly substituted for Michael at the wedding, and though Karl protests, the ceremony proceeds. The regent's duplicity is exposed by Flavia, and all ends happily.