The earliest instance of the eagle as a definitely heraldic charge upon a shield would appear to be its appearance upon the Great Seal of the Markgrave Leopold of Austria in 1136, where the equestrian figure of the Markgrave carries a shield so charged. More or less regularly, subsequently to the reign of Frederick Barbarossa, elected King of the Romans in 1152, and crowned as Emperor in 1155, the eagle with one or two heads (there seems originally to have been little unanimity upon the point) seems to have become the recognised heraldic symbol of the Holy Roman Empire; and the seal of Richard, Earl of Cornwall, elected King of the Romans in 1257, shows his arms ["Argent, a lion rampant gules, within a bordure sable, bezanté"] displayed upon the breast of an eagle; but no properly authenticated contemporary instance of the use of this eagle by the Earl of Cornwall is found in this country. The origin of the double-headed eagle (Fig. 455) has been the subject of endless controversy, the tale one is usually taught to believe being that it originated in the dimidiation upon one shield of two separate coats {238} of arms. Nisbet states that the Imperial eagle was "not one eagle with two heads, but two eagles, the one laid upon the other, and their heads separate, looking different ways, which represent the two heads of the Empire after it was divided into East and West." The whole discussion is an apt example of the habit of earlier writers to find or provide hidden meanings and symbolisms when no such meanings existed. The real truth undoubtedly is that the double-headed eagle was an accepted figure long before heraldry came into existence, and that when the displayed eagle was usurped by armory as one of its peculiarly heraldic figures, the single-headed and double-headed varieties were used indifferently, until the double-headed eagle became stereotyped as the Imperial emblem. Napoleon, however, reverted to the single-headed eagle, and the present German Imperial eagle has likewise only one head. [Illustration: FIG. 456.--Napoleonic Eagle.] The Imperial eagle of Napoleon had little in keeping with then existing armorial types of the bird. There can be little doubt that the model upon which it was based was the Roman Eagle of the Cæsars as it figured upon the head of the Roman standards. In English terms of blazon the Napoleonic eagle would be: "An eagle displayed with wings inverted, the head to the sinister, standing upon a thunderbolt or" (Fig. 456). The then existing double-headed eagles of Austria and Russia probably supply the reason why, when the German Empire was created, the Prussian eagle in a modified form was preferred to the resuscitation of the older double-headed eagle, which had theretofore been more usually accepted as the symbol of Empire.