In 1902, Princess Beatrice had a romance with Russian Grand Duke Michael, the younger brother of Tsar Nicholas II, and at that time the heir presumptive to the Imperial Throne. She began receiving letters from him in September 1902 and, although he was a Russian Grand Duke and she now a German Princess, they corresponded in English, and he nicknamed her "Sima". However she was prevented from marrying the Grand Duke as the Russian Orthodox Church forbade the marriage of first cousins. Although such marriages had been allowed previously in the House of Romanov (Grand Duchess Catherine Pavlovna, whose hand was denied to Napoleon I, was twice allowed to wed first cousins; her descendants became the Russian branch of the Dukes of Oldenburg), the devout Nicholas II, official head of Russia's church, refused to relax the rules for the sake of his brother.