Bulla Aurea (GOLDEN BULL), a fundamental law of the Holy Roman Empire, probably the best known of all the many ordinances of the imperial diet. It takes its name from the golden case in which the seal attached to the document proclaiming the decree was placed. The law was signed by the Emperor Charles IV, January, 1356, during the Diet of Nuremberg, and was revised at the Diet of Metz in November of the same year. The contents of the Bulla Aurea were of constitutional importance for the empire. It ordained that each emperor should be chosen by election, the right of voting being vested in electoral princes, the number of whom was fixed at seven. As electors the edict appointed, on the one side, the three ecclesiastical princes most closely connected with the history of the empire, i.e. the Archbishops of Mainz, Trier, and Cologne. On the other side, the law settled the question, as far as it was still in dispute, as to whether the electoral vote pertained to certain secular principalities or to certain ruling families. It ordained that the right belonged to Bohemia, the Rhenish Palatinate, Saxony (Sachsen-Wittenberg), and the Mark of Brandenburg; this made the secular electors the King of Bohemia, the Count Palatine of the Rhine, the Duke of Saxony, and the Margrave of Brandenburg. The Bull also defined the powers given by the imperial constitution to the electors, taken as a body, and to certain individual electors separately, both during a vacancy of the throne and during an imperial reign. Thus the document granted to the electors in their character as rulers of principalities certain privileges which had been originally reserved to the German king and emperor and were the signs of his sovereignty. The transfer of these rights to subordinate rulers would, necessarily, gradually make them independent of the head of the empire. The Bull also provided for the preservation of peace in the empire and enacted measures for holding in check the increasing political importance of the rising free cities. In the main the law was intended to confirm rights which had already had a historical development and to settle disputed details of these rights. Constitutional law in the Holy Roman Empire reached its full growth between the years 1220 and 1555. As to the position of the “Golden Bull” in connection with this development, see Germany.