Pope Benedict XVI on Sunday celebrated a baptism mass in the Sistine Chapel with his back turned to the congregation, adopting the disused liturgical tradition for a second time as pontiff.
Celebrating the Roman Catholic Church's Feast of the Lord's Baptism marking the end of the Christmas season, Benedict baptised 13 infants and devoted most of his homily to the family and the Christian education of children.
"The child is not the property of his parents but is placed under their responsibility by the Creator... to become a free child of God," he said.
The Vatican's Office of Liturgical Celebrations said the pope preferred to face the altar below Michelangelo's masterpiece "Last Judgement" so as "not to alter the beauty and harmony" of the hallowed Sistine Chapel.
The pope, who was elected in 2005, also celebrated last year's Lord's Baptism facing the altar.
As Cardinal Joseph Ratzinger and the head of the Vatican's doctrinal watchdog, the Congregation for the Doctrine of the Faith, he lamented the decision by the Second Vatican Council in the mid-1960s that a priest should face the congregation during mass.
He argued that the change created a circle of congregation and celebrant closed in on itself rather than being turned together towards their object of worship.
In July 2007, Benedict issued a decree allowing "groups of the faithful" to ask for regular celebrations of the 16th-century Latin mass, capping a long campaign that threatened to divide the Church.
The form of the Latin mass was set under the reign of Pius V at the Council of Trent -- and is thus known as the Tridentine mass -- but it was discarded during the modernising reforms of the Second Vatican Council.