§ 110.4. =Benedict XII.=, A.D. 1334-1342, would probably have yielded to the urgent entreaties of the Romans to return to Rome had not his cardinals been so keenly opposed. He then built a palace at Avignon of imposing magnitude, as though the papacy were to have an eternal residence there. Louis the Bavarian retracted his heretical sentiments in order to get the ban removed and to obtain an orderly coronation. The first diet of the electoral union was held at Rhense near Mainz, in A.D. 1338, where it was declared that the election of a German king and emperor was, by God’s appointment, the sole privilege of the elector-princes, and needed not the confirmation or approval of the pope. This encouraged Louis to assert anew his imperial pretensions. Benedict’s successor =Clement VI.=, A.D. 1342-1352, added by purchase in A.D. 1348 the city of Avignon to the county of Venaissin, which Philip III. had gifted to the papal chair in A.D. 1273. Both continued in the possession of the Roman court till A.D. 1791 (§ 165, 13). Louis, now at feud with some of the powerful German nobles, sought to make terms of peace with the new pope. But Clement was not conciliatory, and made the unheard of demand that Louis should not only annul all his previous ordinances, but also should in future issue no enactment in the empire without permission of the papal see; and on Maunday Thursday, A.D. 1346, he pronounced him without title or dignity and called upon the electors to make a new choice, which, if they failed to do, he would proceed to do himself. As fittest candidate he recommended Charles of Bohemia, who was actually chosen by the five electors who answered the summons, under the title of =Charles IV.=, A.D. 1346-1378, and had his election confirmed by the pope. The new emperor solemnly promised never to set foot on the domains of the Roman church without express papal permission, and to remain in Rome only so long as was required for his coronation. Louis died before he was able to engage in war with his rival, and when, six months later, the next choice of Louis’ party also died, Charles was acknowledged without a dissentient voice. He was crowned emperor in Rome by a cardinal appointed by Innocent VI., in A.D. 1355. Without doing anything to restore the imperial prestige in Italy, Charles went back like a fugitive to Germany, despised by Guelphs and Ghibellines. But in the following year, at the Diet of Nuremberg, he passed a new imperial law in the so called Golden Bull of A.D. 1356, according to which the election of emperor was to be made at Frankfort, by three clerical electors (Mainz, Cologne, and Treves) and four temporal princes (Bohemia, the Palatine of the Rhine, Saxony, and Brandenburg), and he appeased the pope’s wrath by various concessions to the curia and the clergy.