VATICAN CITY (AP) -- Benedict XVI always cast himself as the reluctant pope, a shy bookworm who preferred solitary walks in the Alps to the public glare and the majesty of Vatican pageantry. But once in office, he never shied from charting the Catholic Church on the course he thought it needed -- a determination reflected in his stunning announcement Monday that he would be the first pope to resign since 1415.
While taking the Vatican and world by surprise, Benedict had laid the groundwork for the decision years ago, saying popes have the obligation to resign if they get too old or sick to carry on. And to many, his decision was perfectly in keeping with a man who had dedicated his life to the church, showing his love for the institution and a courageous acknowledgment that it needed new blood to confront the future.
"This decision, even though it fills us with surprise -- and at first glance leaves us with many questions -- will be as he said for the good of the church," said Cardinal Angelo Scola, the archbishop of Milan, who is a leading contender to succeed Benedict.
The German theologian, whose mission was to reawaken Christianity in a secularized Europe, grew increasingly frail as he shouldered the monumental task of purging the Catholic world of a sex abuse scandal that festered under John Paul II and exploded during his reign into the church's biggest crisis in decades, if not centuries.
More recently, he bore the painful burden of betrayal by one of his closest aides: Benedict's own butler was convicted by a Vatican court of stealing the pontiff's personal papers and giving them to a journalist, one of the gravest breaches of papal security in modern times.
All the while, Benedict pursued his single-minded vision to rekindle faith in a world which, he frequently lamented, seemed to think it could do without God.
"In vast areas of the world today, there is a strange forgetfulness of God," he told 1 million young people gathered on a vast field for his first foreign trip as pope, World Youth Day in Cologne, Germany in 2005. "It seems as if everything would be just the same even without Him."
With some decisive, often controversial moves, Benedict tried to remind Europe of its Christian heritage and set the Catholic Church on a conservative, tradition-minded path that often alienated progressives and thrilled conservatives.
The Vatican's crackdown on American nuns -- accused of straying from church doctrine in pursuing social justice issues rather than stressing core church teaching on abortion and homosexuality -- left a bitter taste for many American Catholics.
But conservatives cheered his championing of the pre-Vatican II church and his insistence on tradition, even if it cost the church popularity among liberals.
As he said in his 1996 book "Salt of the Earth," a smaller but purer church may be necessary. "Maybe we are facing a new and different kind of epoch in the church's history, where Christianity will again be characterized more by the mustard seed, where it will exist in small, seemingly insignificant groups that nonetheless live an intensive struggle against evil and bring the good into the world -- that let God in," he said then.
Yet his papacy will be forever intertwined with the sex abuse scandal.
Over the course of just a few months in 2010, thousands of people in Europe, Australia, South America and beyond came forward with reports of priests who raped and molested them as children, and bishops who covered up the crimes.
Documents revealed that the Vatican knew well of the problem yet turned a blind eye for decades, at times rebuffing bishops who tried to do the right thing.
Benedict had firsthand knowledge of the scope of the problem since his old office, the Congregation for the Doctrine of the Faith which he had headed since 1982, was responsible for dealing with abuse cases.
He met with victims across the globe, wept with them and prayed with them. He promised that the church must "do everything possible" to ensure such crimes never happen again. The Vatican updated its legal code to extend the statute of limitations for cases and told bishops' conferences around the world to come up with guidelines to prevent abuse.
But Benedict never admitted any personal or Vatican failure. Much to the dismay of victims, he never took action against bishops who ignored or covered up the abuse of their priests or moved known pedophiles to new posts where they abused again.