A look back at Pope Benedict XVI

Pope Benedict XVI announced Monday that he will resign on Feb. 28. The 85-year-old pope is the first pontiff to resign in nearly 600 years. In a statement, Benedict emphasized that carrying out the duties of being pope — the leader of more than a billion Roman Catholics worldwide — requires "both strength of mind and body." He says he is simply too infirm to carry on.

Here's a look at Pope Benedict XVI's career in photos.