Pope Francis married 20 Roman Catholic couples of different ages and backgrounds, some of whom have already lived together and had children, in a traditional ceremony at St. Peter’s Basilica. (Reuters)

Pope Francis presided over the wedding of 20 couples on Sunday, some of whom had lived together and had children, in the latest sign that the Argentine pontiff wants the Catholic Church to be more open and inclusive.

In the first wedding ceremony of his 18-month-old papacy, Francis took each couple through their vows in turn — including Gabriella and Guido, who have children and thought such a marriage would be impossible, the official broadcasting service Vatican Radio said.

“The people getting married on Sunday are couples like many others,” the Diocese of Rome said in a statement. “Some already live together, some already have children.”

The nuptials were the first of their kind in the Vatican since Pope John Paul II presided over a wedding in 2000, when he was the leader of the world’s 1.3 billion Catholics.

Francis, who is the first non-European pope in 1,300 years, has expressed tolerance on many topics that are traditionally taboo in the church. On homosexuality, he once remarked, “If someone is gay and he searches for the Lord and has goodwill, who am I to judge?”

His approach contrasts with that of his predecessor, the German Pope Benedict XVI, who said threats to the traditional family undermined the future of humanity.

Bishops from all over the world are scheduled to come to the Vatican next month for a major meeting on the family, which the Jesuit pope referred to in the homily to Sunday’s Mass as the “bricks” on which society is built.

The bishops are expected to discuss issues such as marriage, divorce and contraception at the synod, which will be held Oct. 5-19.

The pope has said that the church must end its obsession with teachings on abortion, contraception and homosexuality, and must become more merciful, or risk collapsing “like a house of cards.”