The Golden Bull of 1356 was a decree issued by a Reichstag in Nuremberg headed by Emperor Charles IV, Holy Roman Emperor (see Diet of Nuremberg) that fixed, for a period of more than four hundred years, important aspects of the constitutional structure of the Holy Roman Empire. It was named the Golden Bull for the golden seal it carried.
The Golden Bull explicitly named the seven Kurfürsten or prince-electors who were to choose the King of the Romans, who would then usually be crowned Holy Roman Emperor by the Pope later. The seven prince-electors were, "Three prelates were archchancellors of Germany (Mainz), Gaul and Burgundy (Trier), and Italy (Cologne) respectively : the Bohemia cupbearer, the Palsgrave seneschal, Saxony marshal, and Brandenburg chamberlain.” Consequently, the Bull speaks of the rex in imperatorem promovendus, the "king to be promoted emperor" — although the distinction between the two titles would become increasingly irrelevant (and virtually nonexistent after 1508).
Even though the practice of election had existed earlier and most of the dukes named in the Golden Bull were involved in the election, and although the practice had mostly been written down in an earlier document, the declaration at Rhense from 1338, the Golden Bull was more precise in several ways. For one, the dukeships of the Electors were declared indivisible, and succession was regulated for them to ensure that the votes would never split. Secondly, the Bull prescribed that four votes would always suffice to elect the new King; as a result, three Electors could no longer block the election, and the principle of majority voting was explicitly stated for the first time in the Empire. Finally, the Bull cemented a number of privileges for the Kurfürsten to confirm their elevated role in the Empire. It is therefore also a milestone in the establishment of largely independent states in the Empire, a process to be concluded only centuries later, notably with the 1648 Peace of Westphalia.


Besides regulating the election process, the 31 chapters of the Golden Bull contained many minor decrees. For instance, it also defined the order of marching when the emperor was present, both with and without his insignia. A relatively major decision was made in chapter 15, where Charles IV outlawed any conjurationes, confederationes, and conspirationes, meaning in particular the city alliances (Städtebünde), but also other communal leagues that had sprung up through the communal movement in mediæval Europe. Most Städtebünde were subsequently dissolved, sometimes forcibly, and where refounded, their political influence was much reduced. Thus the Golden Bull also strengthened the nobility in general to the detriment of the cities.
The Pope's involvement with the Golden Bull of 1356 was basically nonexistent, which was significant in the history of relations between the Popes and the Emperors. When Charles IV laid down procedure for electing a King of the Romans, he didn't mention anything about receiving papal confirmation of the election. However, Pope Innocent VI did not protest this because he needed Charles’s support against the Visconti. Pope Innocent continued to have good relations with Charles IV after the Golden Bull of 1356. He remained Pope from 1352-1362.