Ludwig of Bavaria
Marsilius wrote "Defensor pacis" in 1324. This treatise was written in the context of a power struggle between Pope John XXII and Louis of Bavaria (or Ludwig of Bavaria), the elected candidate for Holy Roman Emperor. Louis' policies in the Italian peninsula, where the Empire had important territories, threatened papal territorial sovereignty. In 1323 Louis had sent an army to Italy to protect Milan against the powerful Kingdom of Naples. Naples, along with France, was a strong ally of John XXII. John excommunicated Louis and demanded that he relinquish his claim to the imperial crown. Louis responded to John XXII with fresh provocations.