A weary Pope Benedict XVI has celebrated his final public Mass as pontiff.
He presided over Ash Wednesday services just hours after explaining his decision to step down directly to the faithful.
The mood inside St Peter's Basilica was sombre during the Mass, as if the weight of Benedict's decision had finally registered with the thousands of faithful present.
But the basilica erupted in a rousing, minutes-long standing ovation as Benedict exited, bringing tears to the eyes of some of his closest collaborators.
"We wouldn't be sincere, Your Holiness, if we didn't tell you that there's a veil of sadness on our hearts this evening," Cardinal Tarcisio Bertone, Benedict's long-time deputy, told the pope at the end of the service, his voice breaking.
"Thank you for having given us the luminous example of the simple and humble worker in the vineyard of the Lord," he said, quoting Benedict's own words when he was elected pope.
"Viva il papa!" the crowd yelled as Benedict stepped off the altar.
Ash Wednesday marks the start of Lent, the most solemn season on the church's liturgical calendar that ends with Holy Week, when the faithful commemorate the death of Christ and his resurrection on Easter Sunday. By this Easter, on March 31, the church will likely have a new pope.
The scene was festive earlier in the day, when Benedict took the extraordinary step of speaking directly to his flock about why he had broken with 600 years of tradition and decided to retire on February 28.
"As you know, I have decided to renounce the ministry that the Lord gave to me on April 19, 2005," Benedict said, to warm applause. "I did this in full liberty for the good of the church."