This title refers to someone set up as Bishop of Rome in opposition to the one already holding the See; 2 lived in Avignon
[DOC] [TLE] Avignon Papacy - Wikipedia [PAR] The Avignon Papacy was the period from 1309 to 1377 during which seven 
successive popes ... Clement declined to move to Rome, remaining in France, 
and in 1309, ... after only two popes had reigned in opposition to the Papacy in 
Rome.