Pontiff is the first to abdicate in modern times.
Pope Benedict's decision to step down came as a surprise shock to many.
He's the first Pope to abdicate in 600 years.
The 85-year-old cited fading health, saying, in a statement released Monday:
"I have come to the certainty that my strengths, due to an advanced age, are no longer suited to an adequate exercise of my ministry."
Many feel the next Pope ought to be more charismatic and stronger, "a man in full possession of his physical powers," according to NBC News Vatican Analyst George Weigel.
Pope Benedict will officially step down February 28th.
Soon after that the college of Cardinals will elect a new Pope who will face something new: a living former Pope looking over his shoulder.