Once in Venice, Grand Duke Andrei accompanied his mother via train to Cannes, on the French Riviera. Grand Duchess Maria Pavlovna died a few months later in September 1920. During her illness in Contrexéville, Grand Duke Andrei was reunited for the first time in exile with his three siblings. At his mother's death the last obstacle for Grand Duke Andrei to marry Mathilde Kchessinska was lifted. Andrei asked permission to marry Kchessinska from his brother Grand Duke Kirill and from Empress Maria Feodorovna, widow of Tsar Alexander III, the senior members of the Romanov family; both gave their consent. Kchessinska, who was of Polish descent, was Catholic, but they were married in a simple ceremony in the Russian Orthodox Church of St. Michael Archangel in Cannes on 30 January 1921. Grand Duke Andrei also claimed paternity of Kchessinska's son, Prince Vladimir Romanovsky-Krasinsky (30 June 1902 – 23 April 1974). In 1924, Grand Duke Andrei's eldest brother, Kirill, proclaimed himself Tsar in exile. Grand Duke Andrei supported his brother's claim. Grand Duke Kirill granted to Mathilde and her son the titles of Princess and Prince Romanovsky-Krasinsky, with the treatment of Serene Highness.