The Times – The swinging 1700s were so like today. History Notebook by Graham Stewart

If the recent upsurge in cohabitation has a historic parallel then it is with the situation that existed before the 1753 Marriage Act. Until then the law had been very clearly against divorce but opaque on what constituted marriage. From our own perspective, we would recognise a large proportion of those who called themselves husband and wife to be nothing more than live-in lovers.

The confusion was caused partly by Innocent III, the 13th-century Pope, who pronounced that weddings did not need a church ceremony or even an officiating priest, merely a spoken exchange of vows in front of two witnesses was sufficient. The one caveat was that the vows — which were for life — had to be freely given and expressed in the present tense.

While the Council of Trent in 1563 tightened up this rather lax understanding in Roman Catholic Europe, Protestant England remained confused as to whether common law, equity law in Chancery or ecclesiastical custom had precedence. The euphemism “married in the eyes of God” usually meant none of the above. One estimate suggests that about half of all unions in the early 18th century involved nothing more than a folk ceremony. In some rural communities where the issue of property rights was unlikely to end in litigation, local custom deemed a couple married as soon as they had whispered a few sweet nothings and started sleeping together. If we adopted such criteria today, the marriage rate would be greatly stimulated, as would the incidence of bigamy.

In 1753 Lord Chancellor Hardwicke introduced legislation establishing that the only grounds for a legal marriage were that it took place in church under the guidance of a clergyman and was preceded by banns or an official licence. “Can passion be restrained by law?” objected one Tory MP at the time. As a third of brides were pregnant on their wedding day, the answer appeared to be “no”. Similarly, from today’s equally lax perspective, it seems that 20th-century couples were atypically obedient to the proprieties of Church and State.

Yes they do. Or did, as of 4 August, 2001:

BBC – Wedding banns ‘may be scrapped’

The ancient tradition of reading marriage banns may be abandoned to encourage more young people to have church weddings, it has emerged.

So we can attribute the continued slump to the fact that apparently they didn’t follow through:

Wiki – Banns of marriage