The French cardinals return with their “antipope” to Avignon, thereby initiating the so-called Western Schism or Papal Schism (also known as the Great Schism of Western Christianity).

Clement's supporters include Queen Joan I of Naples and forty-seven-year-old Spanish churchman Pedro de Luna, who had been appointed cardinal in 1375 by Pope Gregory XI and had participated in the controversial conclave that had elected Gregory's successor.

Western, or Roman, Catholics have continuously debated the convoking and authority of councils.

Although all the bishops and theologians agree that the pope should have special prerogatives, reformers, who have for centuries claimed that protesters can appeal their grievances from the pope to a council, have formulated a theory of conciliarism: the idea that a council is ultimately above the pope.

The Western Schism in 1378 brings this debate to a head, since there are now two (and will later be three) popes.