The move was opposed by many conservatives and the Catholic Church in France, prompting hundreds of thousands of people to turn out for protest marches in Paris as politicians debated the bill.

CNN: French president signs same-sex marriage bill into law

It was harder, you might think, for the Church of England and the Catholic establishment in France to explain their support of the caliphate.

ECONOMIST: The Crimean war

The Catholic church controlled France's schools in the 19th century and frowned on the teaching of science.

FORBES: Eerily Prescient

In 1980, Pope John Paul II arrived in France on the first visit by the head of the Roman Catholic Church since the early 19th century.

CNN: News Almanac

But the measure has aroused stronger than expected opposition in France - a country where the Catholic Church was thought to have lost much of its influence over the public.

BBC: Same-sex marriage: French parliament approves new law