VATICAN CITY – With a humble "Grazie" as bishops doffed their mitres and applause echoed through St. Peter's Basilica, a frail Pope Benedict XVI began his long farewell by presiding over Ash Wednesday services in a tearful, final public Mass.

"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," said Cardinal Tarcisio Bertone, Benedict's longtime deputy, his voice breaking.

"Thank you for having given us the luminous example of the simple and humble worker in the vineyard of the Lord," Bertone said, quoting Benedict's own words when he first appeared before the faithful above St. Peter's Square after he was elected pope.