Francis’ successor will be selected by cardinals at the conclave that begins on May 7. Cardinals, known as the “princes of the church,” rank just below the pope in the Roman Catholic Church; together, they are known as the College of Cardinals. When a pope dies, the college chooses a successor.

There are currently 135 cardinals who are under age 80 and eligible to vote in the conclave, hailing from 71 different countries in the most geographically diverse conclave in history. Already two have formally told the Holy See that they cannot attend for health reasons, bringing the number of men who will enter the Sistine Chapel down to 133.