"Thank you, I am very moved," he said in Italian. His unusually personal remarks included an admission that "there were moments ... when the seas were rough and the wind blew against us and it seemed that the Lord was sleeping".
Once the chair of St Peter is vacant, cardinals who have assembled from around the world for Benedict's farewell will begin planning the closed-door conclave that will elect his successor.
One of the first questions facing these "princes of the Church" is when the 115 cardinal electors should enter the Sistine Chapel for the voting. They will hold a first meeting on Friday but a decision may not come until next week.
The Vatican seems to be aiming for an election by mid-March so the new pope can be installed in office before Palm Sunday on March 24 and lead the Holy Week services that culminate in Easter on the following Sunday.
In the meantime, the cardinals will hold daily consultations at the Vatican at which they discuss issues facing the Church, get to know each other better and size up potential candidates for the 2,000-year-old post of pope.