In ancient Rome, tyrannical Emperor Caligula is assassinated through the machinations of Messalina. She then makes a conquest of Marcus, who forces the Senate to name her husband, Claudius, as emperor. Messalina's wicked ways continue when she falls in love with Ennio, a slave. Ennio is also loved by Egyptian princess Mirit, but he loves neither of them, preferring the company of Ela, a Greek slave.

In Montegro brothers Stefan and Michael kidnap American heiress Delight Warren. Stefan marries her so he can claim her wealth, but then they fall in love.

Elga Pulaski and her brother Ossip live in Warsaw. They belong to a secret society whose goal is to liberate Poland and Russia from the Romanoffs. Elga is loved by Baron Jan Slozek. But Slozek is a spy who has Ossip and other members of the society arrested. When Slozek is slain, Ossip is the key suspect. He escapes to America with his sister. There, Elga meets Norman Hutchinson, and marries him without telling him her past. When Hutchinson learns the truth, he leaves Elga. Eventually, when Elga appeals to him, he sees the light.

A story of the First World War, told in semi-documentary style, focusing on the iniquities of the German war machine, and with its dramatic center the sinking by a German U-boat of the passenger liner Lusitania in 1915.

Florence Brent is the daughter of Bennington Brent, who runs a successful laundry business. Florence's childhood friend, John Oglesby, is a Congressman. When Florence visits her friend, Eleanor Williamson, in Washington D.C., she meets Eleanor's fiancé, who is a Count. The Duke of Buritz, a countryman of the Count, tries to corrupt Oglesby for political reasons. Meanwhile, the Count breaks his engagement to Eleanor, having become enamored of Florence. Oglesby eventually exposes the duplicity of the Count and Duke.

Teodora, a Roman courtesan and former slave girl, marries the Roman emperor Justinian and assumes the throne as Empress of Rome. But a love affair with a handsome Greek whom she meets in Byzantium leads to revolution and armed conflict in both Byzantium and Rome.