That the world's 1.2 billion Catholics were stunned by Pope Benedict XVI's surprise retirement announcement Monday would be an understatement. Not since Pope Pope Gregory XII in 1415 has the church had to replace anybody but a deceased leader.

Even the cardinals surrounding the 85-year-old religious leader were taken aback when Benedict 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 the demands of the job.

Whether this will set a precedent moving forward remains to be seen. The practice of retaining the position for life appears rooted in the belief that schisms could materialize if two popes were alive at the same time.

Also remaining to be seen is what religious scholars and historians will make of Benedict's not-quite-8-year papacy.

The former Cardinal Joseph Ratzinger succeeded the wildly popular Pope John Paul II in 2005. The German theologian sought to restore traditional practice and worship to the church in an attempt to fix what he said was "the erroneous interpretation" of Vatican II. The Second Vatican Council was a series of meetings in the early 1960s designed to bring Catholics into the modern world.

Benedict reauthorized the Latin Mass. He re-established relations with traditionalist orders that had splintered off as Vatican II took hold. He sought to re-evangelize a more secular West, particularly Europe. He cracked down on American nuns he saw more interested in pursuing social justice than traditional core teachings on abortion and homosexuality. Anglicans upset about women priest and gay bishops in their own churches were invited to become Catholics.

The pope's mission was sidelined somewhat by the sex abuse scandal that erupted during John Paul's reign and became a global crisis during his own. An international money-laundering operation was tied to the Holy See, and was followed by Benedict's personal butler stealing documents and attempting to share them with the world.

Through it all, Benedict has been resolute about shoring up Catholic identity. His steadfastness is heralded by conservative Catholics; not so much by progressive members.

Whomever his successor, the issues will remain. Benedict simply wasn't on the job long enough to resolve them, nor begin to counter the serious competition for parishioners posed by other churches. The 266th pope will have a lot on his plate.

We congratulate Benedict for recognizing the limitations aging has imposed on him. In the end, Pope Benedict XVI might well be remembered more for his tradition-breaking resignation than his attempts to restore tradition to the Catholic Church.

Editorial by Patrick Lowry

plowry@dailynews.net