In what he recognized as his failing strength of "mind and body," Pope Benedict XVI announced Monday that he would resign as head of the Catholic church, a move that hasn't happened in the Roman Catholic Church since 1415 and that is likely to pave the way for a new pontiff by Easter.

"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," Benedict said in a statement.

A papal spokesman added during a briefing with reporters that Pope Benedict had been thinking about the move for some time, saying it wasn't due to an illness. Father Lombardi, the spokesman, said the pope would retire to a life of prayer and writing. He also said the pontiff had "no fear" of any potential schism in the church as a consequence of the pope's resignation.

Describing his decision as being "of great importance for the life of the church," Benedict told cardinals that "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 bark of Saint Peter and proclaim the Gospel, both strength of mind and body are necessary."

Benedict's decision, which he described as being "of great importance for the life of the church," marks the first papal resignation since Pope Gregory XII reluctantly stepped down in 1415 to end a dispute with a rival claimant to the papacy. The last pope to resign willingly was Celestine V in 1294 after reigning for only five months.

The resignation, which the Vatican said would take place as of 8 p.m. on Feb. 28, will give way to a conclave, a gathering of cardinals who will elect the new pope. Normally, after a pope dies, there is a nine-day mourning period before the selection his successor. This time, the process can begin right away, said Greg Burke, the Vatican's media adviser. "This means we'll have a new pope by Easter," he added. The holiday falls on March 31 this year.