Based on the novel by Hervey Allen, an orphan raised in a convent and by a merchant is separated from his wife doing business for his foster father.
An invalid Don Luis (Claude Rains) takes his bride Maria (Anita Louise) to Versailles, where she meets her lover Denis (Louis Hayward). When Don Luis shows he is well, Denis fights him with a sword and is killed. Maria gives birth to a boy and dies. Don Luis gives the baby to a convent and tells Maria's father John Bonnyfeather (Edmund Gwenn) that she and the baby died. Anthony (Billy Mauch) is raised by Father Xavier (Henry O'Neill) until the age of ten, when he is adopted as an apprentice by Bonnyfeather, who discovers he is Maria's child.
Years later Anthony Adverse (Fredric March) wants to marry Angela Giusseppi (Oliva de Havilland), the cook's daughter; but her father wins the lottery and moves the family away. Anthony meets Vincente Nolle (Donald Woods), son of a banker. When Napoleon invades Italy, Bonnyfeather closes his business and names Anthony his heir. At the opera Anthony sees Angela singing. He calls on her, and they get married. Bonnyfeather asks Anthony to go to Havana to collect a large debt from Gallegos & Son. Anthony misses meeting Angela and goes alone. Bonnyfeather's representative Carlo Cibo (Akim Tamiroff) greets Anthony in Havana and says that Gallegos has nothing but slave trading in Africa. Anthony helps the monk Francois (Pedro de Cordoba) stop the whipping of a slave.
Anthony takes Francois to Africa and for three years engages in slave trading to get the debt. Neleta (Steffi Duna) asks Anthony not to leave. Francois helps the rejected slaves, while Anthony gives orders for the trading. Anthony tells Francois he is staying after the debt was collected for the money. During the rainy season the tormented Anthony goes to Francois sick with fever. Neleta keeps Francois away from Anthony by lying to him; but Anthony goes to Francois and finds him dying. Anthony promises to leave Africa.
Anthony learns that Bonnyfeather died, and the housekeeper Faith (Gale Sondergard) will get the estate if he does not return. Anthony calls on her and meets Don Luis, telling him he was raised at a convent. Faith blackmails Don Luis into marrying her. Anthony goes to Paris for the will and survives an attempted ambush on the road in the Alps by Don Luis and Faith. Don Luis tells a French soldier Anthony is an English spy, and Anthony is arrested; but Vincente gets him released. Vincente tells Anthony that he loaned money to Napoleon and is broke. Anthony loans Vincente his inheritance. At a masked ball Napoleon (Rollo Lloyd) dances with Angela, and she sees Anthony. De Bruille tells him where Angela is, and Anthony kisses her and meets his son. Napoleon plans to send Anthony to Mexico to get the gold, and Angela tells him to go. At the opera Anthony realizes that Angela is Napoleon's mistress. She sends their son to Anthony with a note saying she won't see him again. Anthony sails with his son and tells him that the Adverse name was given its mind by Father Xavier, its soul by Francois, and its heart by Angela.
This historical adventure story shows how an orphan's character is forged by adversity. Seeking fortune on behalf of his foster father, Anthony is corrupted in the slave trade and loses his wife; but he gains his son when she chooses to stay with Napoleon. The selfish schemes of Don Luis and Faith fail.