Pope Francis on Sunday described the emotional encounter he had with a Muslim man on the Greek island of Lesbos whose Christian wife was killed by extremists.
He recounted the story before hundreds of believers in St Peter's Square calling the woman "a martyr."
Francis met the 40-year-old man and his two sons on Saturday. "He is a Muslim and told me that he had married a Christian. They loved and respected each other."
"But, unfortunately, the woman's throat was slit by terrorists because she refused to relinquish Christ and leave her faith," the pope said, describing how her husband wept bitterly as he spoke of her.
On Saturday, Francis made a five-hour visit to Lesbos, one of the flashpoints in Europe's migration crisis, where he visited a refugee centre.
Three families of refugees from Syria, 12 people in total, including six children, returned with him to Rome on his plane.