Pope Benedict on Sunday celebrated a solemn Mass in St Peter's Basilica with the new cardinals, a day after he raised them to the highest rank in the Church under him.
"The new dignity that has been conferred upon you is intended to show appreciation for the faithful labour you have carried out in the Lord's vineyard, to honour the communities and nations from which you come and which you represent so worthily in the Church," he said in his homily.
The Cardinals who are the Pope's closest aides in the Vatican and around the world and those under 80 are part of the exclusive group who will one day elect one of their own to succeed him as leader of the world's 1.3 billion Roman Catholics.
They lead major Archdioceses and run Vatican departments that help the Pope decide Church policy and doctrine that can affect the lives of Catholics worldwide.
Among the group, New York's Archbishop Timothy Dolan, is seen as a possible future candidate to become the first American Pope.