I understand this much:
The Pope is the heir of St. Peter.
St. Peter was the first Bishop of Rome.
The Pope is the Bishop of Rome.
Now what I don’t understand:
Were the Avignon Popes the Bishops of Avignon, the Bishops of Rome or the Bishops of both?
When the Popes were in Avignon, did Rome have another bishop? I don’t mean another Pope, but another bishop who was empowered to run the diocese and perform the pastoral duties with or without the title Bishop of Rome?