The legendary lover saves his queen from treason.

Near London, in the 17th century, notorious Lothario Don Juan barely escapes an angry husband, when he and his friend, Leporello, are stopped by a company of soldiers assigned to keep the road clear to accommodate a Spanish duke. Desperate to avoid the pursuing husband, Don Juan pretends to be the duke, only to discover that he is expected to marry Lady Diana. As Diana is beautiful, Don Juan decides to take advantage of the situation, but is thwarted by the arrival of the real duke. Don Juan and Leporello are subsequently arrested and ordered to be deported to Spain. Before Don Juan leaves England, Count De Polan, the Spanish ambassador, gives him a written introduction to Queen Margaret, the Spanish king's consort, and asks him to help prevent an impending war between Spain and England. Once in Spain, Don Juan and Leporello discover that, in their absence, their homeland has become a dispirited place. While they are resting at an inn, a press gang made up of the Duke de Lorca's soldiers arrives and harasses the residents. After Don Juan drives them away at sword point, he is accepted as a hero. The people speak favorably of Margaret, but are disappointed by her husband, King Phillip III, who is greatly influenced by the power-hungry Lorca. When Don Juan presents his letter to Margaret, she chastises him for his dalliance with Lady Diana, which disgraced the state and destroyed the possibility of a political marriage that would have helped prevent war between England and Spain. After Don Juan tells her about Lorca's press gang, she asks him to become a fencing instructor at the Royal Academy. Meanwhile, Lorca's men kidnap De Polan and demand the money he carries for Spain. When De Polan refuses, Lorca imprisons and tortures him. Lorca offers Don Juan a commission in the Spanish Navy and suggests that he increase the size of the academy with men who would then be drafted into the Navy. Don Juan greatly angers Lorca when he turns down the commission, stating that Lorca is apparently preparing for a war that would be disastrous for Spain. Don Juan then reports to Margaret and tells her that he has fallen in love with her. Margaret angrily rejects him, and Don Juan returns to his promiscuous ways. The ensuing scandal enables the king and Lorca to order his exile to the New World. Don Juan escapes, but while making preparations for his departure, he notices a soldier wearing a ring that belongs to De Polan. Learning of De Polan's capture, Don Juan rides to the court to tell Margaret and the king what he knows. Against the wishes of the king, Lorca orders Don Juan's arrest, and he is taken to the fortress to be executed. Leporello and the fencing master help Don Juan escape and together they rescue De Polan. With the help of his fencing students, Don Juan overcomes Lorca and his men. Later, Margaret admits that she returns Don Juan's love, but he replies that he would never jeopardize the future of Spain by taking her away from her position. Instead, he announces that he will leave Spain because he can never have the woman he truly loves. Despite his broken heart, however, Don Juan does not give up his search for beauty and is soon pursuing another lovely young woman.