Answer:
The Pisan popes Alexander V and John XXIII are now considered to be antipopes. Gregory XII's resignation (in 1415) was the last time a pope resigned until Benedict XVI in 2013.
Result: Stabilization between 1417–1429 during the pontificate of Pope Martin V and ...
Date: 1378–1417
Location: Western Christendom (primarily Europe)
Explanation:
