Pope Benedict XVI is to resign at the end of this month after nearly eight years as the head of the Catholic Church, saying he is too old to continue at the age of 85.
The unexpected development – the first papal resignation in nearly 600 years – surprised governments, Vatican-watchers and even his closest aides.
The then Cardinal Joseph Ratzinger became Pope after John Paul II’s death.
The Vatican says it expects a new Pope to be elected before Easter.
The BBC’s Alan Johnston in Rome says the news has come “out of the blue”, and that there was no speculation whatsoever about the move in recent days.
Pope Benedict XVI is to resign on February 28 due to his “deteriorating” health.
He will be the first head of the Roman Catholic Church to resign in almost 600 years, with his departure expected to leave the post vacant for around three weeks.
The 85-year-old German’s resignation letter said: “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.
“Strength of mind and body are necessary, strength 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 pope said, according to the Vatican.
After Benedict’s resignation becomes effective on February 28, cardinals will meet to choose a new leader for the church.