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 can't 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 an acknowledgment that it needed new blood to confront the future.

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.