Why did Pope Clement VI support Charles of Moravia as a rival to Louis IV?

Pope Clement VI supported Charles of Moravia as a rival to Louis IV primarily due to the long-standing conflict between the papacy and the emperor, whom the church had declared a heretic on political grounds.1

The relationship between the two was further strained by Louis’s actions, including his attempt to annul the marriage of Margaret of Carinthia-Tirol to a member of the House of Luxembourg and his subsequent remarriage of her to his own son, which caused a final rupture with the Luxembourg dynasty.1

Clement VI, who had previously served as a teacher to Charles in Paris, encouraged the Luxembourgs to renew heresy proceedings against Louis and demand a new election. Charles of Moravia, in turn, secured the support of the papacy by granting it excessive concessions. This alliance led to Charles being elected king in 1346, with the support of all electoral votes except those held by the House of Wittelsbach.12