VATICAN CITY - Pope Benedict has celebrated his final public Mass as pontiff.
He presided over Ash Wednesday services at St. Peter's Basilica.
The retiring 85-year-old pope was wheeled down the central aisle as a choir sang, preceded by dozens of cardinals.
In his homily, Benedict referred to his pending Feb. 28 resignation and asked for prayers.
At the end of the Mass, the pope's longtime deputy, Cardinal Tarcisio Bertone, thanked him for being an example of a "simple and humble worker in the vineyard of the Lord." Those were the words Benedict himself used when he was elected pope in April 2005.
As the pope made his exit, the basilica erupted in a standing ovation.
Earlier in the day, during his weekly catechism lesson, the pope explained why he had broken with 600 years of tradition and decided to retire, saying he was doing so "for the good of the church."