A ruling on marriage in the Catholic Church at the turn of the 20th century meant separation from a mother and her child forever.

100 years ago a young Presbyterian mother Agnes McCann, who married a Catholic man, had her children removed from her because she refused to comply with a Vatican decree and bring her children up as Catholics.

The children's father took the children and she never saw them again.

The Ne Temere ruling (literally meaning "not rashly" in Latin) came into being on Easter Sunday, 1908 after the Catholic Congregation of the Council regulated canon law of the Church about marriage for practising Roman Catholics.

The most notable effect of the decree was the requirement for a non-Catholic spouses to agree to educate and raise his/her children as Roman Catholics.

In some cases it was also expected for that spouse to convert to Catholicism before the marriage, to ensure compliance.

It meant the Catholic Church would not recognise a marriage between a Protestant and a Catholic unless it took place in a Catholic church.

It also decreed children from the marriage must be brought up as Catholics.

A BBC Radio Ulster documentary called "Mixing Marriages" reporter Barbara Collins discusses the ruling that destroyed several lives at the time, most notably Agnes McCanns.

Collins said, "As a mother of a 20-month-old boy, I could imagine how utterly devastating it must have been for her to lose those dearest to her at such a tender age, and for it to happen at the hands of the man she had once loved."

Collins explains more, "The priest who visited their home in west Belfast in 1910 convinced Agnes's husband Alexander he had been living in sin and his children would be damned.

"Alexander felt he had no choice but to take them from her if she wouldn't capitulate.

"Despite frantic searching, nationwide publicity and beyond, Agnes McCann never saw her children again.

"She was reported as being "broken in health, suffering untold agony of the heart."