Pope benedict's decision to resign sets the stage for a conclave to elect a new pope before the end of March.

All cardinals under the age of 80 are allowed to vote in the conclave, the secret meeting held in the Sistine Chapel where cardinals cast ballots to elect a new pope. As per tradition, the ballots are burned after each voting round; black smoke signals no pope has been chosen, while white smoke means a pope has been elected.

Popes are allowed to resign - church law specifies only that the resignation be "freely made and properly manifested."

Only a handful have done so, however and there’s good reason why it hasn’t become commonplace: Might the existence of two popes - even when one has stepped down - lead to divisions and instability in the church? Might a new resignation precedent lead to pressures on future popes to quit at the slightest hint of infirmity?

Benedict himself raised the possibility of resigning if he were simply too old or sick to continue on in 2010, when he was interviewed for the book "Light of the World."

"If a pope clearly realizes that he is no longer physically, psychologically and spiritually capable of handling the duties of his office, then he has a right, and under some circumstances, also an obligation to resign," Benedict said.

The former Cardinal Joseph Ratzinger had an intimate view as Pope John Paul II, with whom he had worked closely for nearly a quarter-century, suffered through the debilitating end of his papacy.

You can watch Pope Benedict's election below: