A single mother, people who had been married before and couples who have been living together "in sin," including one with a child, were among 20 couples to be married by Pope Francis in a taboo-challenging ceremony at the Vatican on Sunday, BBC News reported. It was the first papal marriage ceremony of its kind in 14 years.

In an attempt to portray the openness of his papacy, Francis had asked to marry 40 people from different social backgrounds representative of a realistic sample of modern couples, Agence France-Press reported.

Marriage "is not an easy road, it's sometimes a contentious trip, but that's life", the pope told the couples, both young and old, as their families gathered for the solemn two-hour ceremony.

"It's normal that couples fight. That always happens, but don't end the day without making peace, even a small gesture is enough," said the pontiff, who donned a red robe for the occasion rather than his usual white, at St. Peter's Basilica in Rome.

One of the couples married was a man, Guido, whose previous marriage was annulled, and his partner Gabriella, a single mother with a daughter from a previous relationship.

Sunday's ceremony comes three weeks before a meeting of Catholic bishops from around the world to discuss church teachings on family matters, including issues of marriage, divorce and conception. "The church ban on allowing divorcees who have remarried to receive communion is one of the key topics up for debate, and resolving deep divisions over the issue inside the church is seen as a key test of Francis' leadership," AFP reported.

The last time a wedding was presided over by a pope was under the leadership of John Paul II in 2000, and before that in 1994.