In a sudden, unexpected announcement, Pope Benedict XVI said he will resign at the end of February.

When he does step down, it will be the first time a pontiff has resigned in nearly 600 years. The 85-year-old leader of the Catholic Church made the announcement today, saying he no longer has the strength to carry out his papal duties. The Pope said he was aware of the "seriousness" of his resignation, but he did so in "full freedom." He will live out his days on Vatican grounds.

The sudden announcement sets the stage for the Vatican to hold a conclave to elect a new pope by mid-March. Pope Benedict will not be participate in that conclave. The Pope had suffered health problems prior to being elected to lead the church, and predicted a short tenure for himself. As Pope, Benedict took advantage of technology. In December, he began using Twitter, where he now has 1.5 million followers.