Who will be the next pope? 133 cardinals have started the secretive, centuries-old ritual to elect a successor to Pope Francis.

Francis’ successor will be selected by cardinals at the conclave that began 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.

Every cardinal has their idea on who the next pope should be, which is the reason why this conclave might go a bit longer than we’ve seen in the past.