Catherine II was empress of Russia, and led her country into the political and cultural life of Europe, carrying on the work begun by Peter the Great.
Alexandra Feodorovna was consort of the Russian Czar Nicholas II. Her rule precipitated the collapse of Russia's imperial government. She was murdered, along with her entire family, in 1918.
Empress Frederick was the oldest child of Queen Victoria and Prince Albert of England. She married the future German Emperor Frederick III in 1858, thusly becoming empress of Germany and queen of Prussia.
Marie-Louise is best known for her marriage to the emperor Napoleon after his divorce from Josephine.
St. Helena, the mother of Constantine the Great, was said to have discovered the cross of Christ.
Theodora was empress of the Byzantine Empire from 527 A.D. to 548 A.D. She greatly influenced her husband, Justinian I's political decisions.
Maria Theresa was an Austrian archduchess, and Holy Roman Empress of the Habsburg Dynasty from 1740 to 1780. She was also Marie Antoinette’s mother.