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In page Princess Eugenia Maximilianovna of Leuchtenberg:

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The couple had one son, Duke Peter Alexandrovich of Oldenburg (21 November 1868 – 11 March 1924).[citation needed] Eugenia had a long-standing friendship with Empress Maria Feodorovna, and the two helped arrange the marriage of Eugenia's son to Marie's daughter, Grand Duchess Olga Alexandrovna.[7][8]