 In the later 17th century Baroque form of mitral crown of Leopold I the peaks of the mitre have been rounded into the hemispherical form Peter the Great would adopt as the Imperial Crown of Russia when he took the title emperor as Russian sovereign.Although it is often assumed that the Imperial Crown made for Otto I with its single arch over its inner red cap was the original prototype for the western imperial crown, it is also possible that the Byzantine imperial crown, which in the twelfth century also became closed with two arches, inspired the western emperors to follow their example and also close their crowns with such a pair of arches.The Imperial Crown is associated with the Imperial Orb and Sceptre, and they are displayed together in the Imperial Treasury at the Hofburg Palace in Vienna, Austria.