In formally adopting the Western term "Emperor" for the ruler of Russia, Peter the Great also adopted Western imperial symbols, including the form of the private crowns ("Hauskrone") used by the Holy Roman Emperors (of which the only surviving example is the Austrian imperial crown of Rudolf II, the Imperial Crown of Austria), in which a circlet with eight fleur-de-lis surrounds a mitre with a high arch extending from the front to the back fleur-de-lis. Already in Austria some baroque representations of this type of crown found on statues of the saints had transformed the two halves of the mitre into two half-spheres, and this is the type of imperial crown used in Russia. Peter’s widow and successor, Catherine I, was the first Russian ruler to wear this form of imperial crown.