This is the first time in 600 years that a pontiff has left office before his term was up. Pope Benedict said he no longer has the strength to fulfill the duties of his office.
The 85-year-old Pope said he has noticed that his strength had deteriorated over recent months "to the extent that I have had to recognize my incapacity to adequately fulfill the ministry entrusted to me."
In a statement from the Vatican, the Pope said:
"For this reason, and well aware of the seriousness of this act, with full freedom I declare that I renounce the ministry of Bishop of Rome, Successor of Saint Peter."
A Vatican spokesman said when the pontiff steps down from his duties at 7 p.m on Feb. 28, it will leave the office vacant until a successor is chosen. Pope Benedict XVI will not be able to vote on his new successor because he is over 80 years old.
This announcement came as a shock to the public and especially to Catholics who have not experienced a resignation like this one since the Middle Ages in the 1400s.