Columbia subject headings:
Harvard subject headings:
Alexander I, Emperor of Russia, 1777-1825.
Holy Alliance.
Krüdener, Barbara Juliane, Freifrau von, 1764-1824.
Mystics--Russia--Biography.
Russia--History--1801-1917--Biography.
Princeton subject headings:
Krüdener, Barbara Julie, Freifrau von, 1764-1824.