Why did Pope John XXII challenge Louis IV’s authority as German king?

Pope John XXII challenged Louis IV’s authority primarily due to a fundamental disagreement over the necessity of papal confirmation for a German king. Guided by canon law and historical precedent, John XXII maintained that Louis could not legally rule or assume the title of king of the Romans until his election was formally approved by the papacy.1

The conflict intensified for several reasons:

• Disputed Election: Following the 1314 election, which resulted in two rival claimants, John XXII sought to keep the empire vacant to decide the issue himself.2
• Imperial Intervention: John XXII viewed Louis’s military and political support for the Ghibellines in Italy as a direct threat to papal interests and an attempt to undermine papal authority in the region.2
• Accusations of Heresy: In 1323, the pope declared Louis guilty of acting as king without confirmation and of aiding heretics, specifically by supporting the Visconti of Milan.2

Louis countered by asserting that election by a majority of princes conferred legitimate authority, independent of papal approval. This defiance led to his excommunication in 1324 and sparked a long-standing constitutional struggle over the independence of the empire.12