Pope Francis has launched a major review of Catholic teaching on the family.
The so-called "extraordinary synod of bishops" opened Sunday at the Vatican.
The two-week meeting could lead to change in the Roman Catholic Church's attitude to marriage, cohabitation, divorce, contraception and other family and social issues.
Nearly 200 bishops and lay people from around the world will examine the gulf between what the Church currently says on these issues and what many believers actually do.
Before Pope Francis opened the meeting, he Tweeted - "let us ask the Lord to show us the way forward."
Last month at St. Peter's Basilica, Francis presided over a mass wedding of 20 couples whose relationships would traditionally be considered sinful.
The wedding included unmarried couples who had been living together and those who already had children.
Some information for this report was provided by AFP.