Екатерина I
Duke Charles Frederick was married to Anna Petrovna, Tsesarevna of Russia and elder daughter of Tsar Peter I and Marta Skavronskaya (who would later become Empress Catherine I of Russia). As Charles was the Swedish heir, Peter saw the marriage as politically useful. Charles Frederick was officially engaged to Anna by Tsar Peter. After the death of Peter in 1725, he was given a place in the council, his own court, palace and income by Catherine I of Russia and married to Anna. Anna was not enthusiastic about the marriage, because of his reputation of consorting with prostitutes.