Two young women were among 12 people whose feet Pope Francis washed and kissed at a traditional ceremony in a Rome youth prison on Holy Thursday.
This was the first time a pontiff has included women in the rite.
The Pope travelled to the Casal del Marmo prison on Rome's outskirts for the mass, which commemorates Jesus' gesture of humility towards his apostles the night before he died.
The ceremony has been traditionally limited to men because all of Jesus' apostles were male.
The Vatican spokesman said two of the 12 whose feet were washed were Muslim inmates.
While the former Cardinal Jorge Bergoglio included women in the rite when he was archbishop of Buenos Aires, it was the first time women had taken part in a papal Holy Thursday ceremony.
Taking the ceremony to a youth prison was also a papal first and Francis, who was elected two weeks ago, said he wanted to be closer to those who were suffering.
All popes in living memory have held the service either in St Peter's or the Basilica of St John in Lateran, which is the Pope's cathedral church in his capacity as bishop of Rome.
In a brief, unscripted homily, the Pope told the young inmates that everyone, including him, had to be in the service of others.
"It is the example of the Lord. He was the most important but he washed the feet of others. The most important must be at the service of others," he said.
Earlier, at a mass in the Vatican Pope Francis urged Catholic priests to devote themselves to helping the poor and suffering instead of worrying about careers as Church "managers".
His homily at his first Holy Thursday mass as pope was the latest sign since his surprise election of his determination that the 1.2 billion-member Church should be closer to the poor.
Archbishop Diarmuid Martin
Meanwhile, in Dublin's Pro-Cathedral, Archbishop Diarmuid Martin commented on the feel-good factor generated by Pope Francis' election.
He also referred to the sentencing last week of a former Dublin priest, Patrick McCabe for indecently assaulting two 13 year-old boys, one of them in the precincts of the Pro-Cathedral.
Archbishop Martin remembered McCabe's victims and the horror they had experienced but gave thanks for the great progress the Church in Ireland has made in safeguarding children.
Much of what Judge Yvonne Murphy had to say about McCabe in her landmark 2009 Report has yet to be published.
It was held back at the request of the State to avoid prejudicing his trial.
The Department of Justice has told RTÉ News that some time ago, the High Court adjourned reviewing the question of full publication until next June.