Pope Benedict XVI made the surprising announcement Monday that he would resign on February 28, stating that his health is simply to fragile to fulfill his duties as the leader of the Roman Catholic faith, and making him the first pontiff to do so in nearly 600 years.  The resignation sets the stage for a conclave to elect a new pope before the end of March.

The 85-year-old pope announced his decision in Latin during a meeting of Vatican cardinals Monday morning, emphasizing that carrying out the duties of  requires “both strength of mind and body.”

“After having repeatedly examined my conscience before God, I have come to the certainty that my strengths due to an advanced age are no longer suited to an adequate exercise of the Petrine ministry,” he told the cardinals.  “I am well aware that this ministry, due to its essential spiritual nature, must be carried out not only by words and deeds, but no less with prayer and suffering.

“However, in today’s world, subject to so many rapid changes and shaken by questions of deep relevance for the life of faith, in order to govern the barque of St. Peter and proclaim the Gospel, both strength of mind and body are necessary-strengths which in the last few months, has deteriorated in me to the extent that I have had to recognize my incapacity to adequately fulfill the ministry entrusted to me.”

The last pope to resign was Pope Gregory XII, who stepped down in 1415 in a deal to end the Great Western Schism among competing papal claimants.  Benedict called his choice “a decision of great importance for the life of the church.”

There are several papal contenders, but no obvious front-runner-the same situation when Benedict was elected in 2005 after the death of Pope John Paul II.  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 the new pope.  As per tradition, the ballots are burned after each voting round; black smoke that snakes out of the chimney means 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.”