The appeal to the Supreme Court in Owens v Owens concerned a defended divorce petition. See HERE for further details and links to video of the appeal hearings).
Defended divorce cases are nowadays relatively rare.
The courts are empowered to grant a decree of divorce on the grounds specified in the Matrimonial Causes Act 1973. Section 1(2) of the Act sets out five gateways (or "facts") which, if proved, will establish "irretrievable breakdown of marriage" and enable a divorce to be decreed. In the Owens case the relevant "fact" is section 1(2)(b) -
" that the respondent has behaved in such a way that the petitioner cannot reasonably be expected to live with the respondent;"
Mrs Owens seeks a divorce but her husband successfully defended the divorce petition before His Honour Judge Tolson QC and also in the Court of Appeal (Civil Division) - Owens v Owens  EWCA Civ 182. Sir James Munby P stated the matter in this way -
"This is an appeal from the refusal of His Honour Judge Tolson QC, sitting in the Central Family Court, to grant a wife a decree nisi of divorce, even though he had, correctly, found as a fact that the marriage has broken down. The judge found that the wife "cannot go on living with the husband" and continued: "He claims to believe that she can, indeed that she will, but in this in my judgment he is deluding himself." Yet the judge dismissed her petition, on the basis that the wife had failed to prove, within the meaning of section 1(2)(b) of the Matrimonial Causes Act 1973, that her husband "has behaved in such a way that [she] cannot reasonably be expected to live with [him]."
The Supreme Court heard Mrs Owens' appeal on 17th May and judgment is awaited.
Divorce has a lengthy and complex legal history. Before the mid-19th century, a divorce permitting remarriage could only be obtained by a Private Act of Parliament. Between 1700 and 1857 there were 314 such Acts, most of them initiated by husbands. This was a very expensive process - £1,000 being a conservative estimate provided no opposition was encountered - (in excess of £1 million today). Needless to say, many married people were condemned to spend their lives in misery brought about by the practical inability to bring their unhappy marriage to an end.
King George IV sought to divorce his wife, Caroline of Brunswick. George hated her and never wanted her to become Queen. Caroline was popular with the British populace, who sympathised with her and who despised the new king for his immoral behaviour. On the basis of the loose evidence collected against her, George attempted to divorce her by introducing the Pains and Penalties Bill to Parliament, but George and the bill were so unpopular, and Caroline so popular with the masses, that it was withdrawn by the government. In July 1821, Caroline was barred from the coronation on the orders of her husband. She fell ill in London and died three weeks later. Her funeral procession passed through London on its way to her native Brunswick, where she was buried.
The Matrimonial Causes Act 1857 brought about certain reforms. The Act created a new civil court to handle divorce and removed this jurisdiction from the ecclesiastical courts. The 1857 Act contained a double standard. A wife's adultery was sufficient to end a marriage but a woman could only divorce her husband if his adultery was compounded by another matrimonial offence. In 1923, a further Act granted a wife the right to divorce her husband for adultery alone.
Further reform came in 1937 when legislation was enacted as a result of the work of Mr A P Herbert MP (Oxford University). Grounds for divorce were extended to unlawful desertion for 2 years or more, cruelty, incurable insanity, incest and sodomy.
Our modern law stems from the Divorce Reform Act 1969 which came into force in 1971. The 1969 reforms arose from a Private Member's Bill steered through the House of Commons by the late Bill Watson MP - see the obituaries at The Independent and The Guardian. The 1969 Act made "irretrievable breakdown of marriage" the basis for divorce. It is interesting that some female MPs described his measure as "a charter to allow Casanovas to do as they please." He responded by saying gently, time and again, "What the Law must recognise is that though marriages are made in heaven, they don't always stay there" and that when a marriage is dead it should be given a decent burial.
The Matrimonial Causes Act 1973 Act consolidated certain enactments relating to matrimonial proceedings, maintenance agreements, and declarations of legitimacy, validity of marriage and British nationality, with amendments to give effect to recommendations of the Law Commission.
Irrespective of the actual outcome of Owens v Owens, there is some pressure for further law reform - See the views of the Nuffield Foundation. Lady Hale, President of the Supreme Court, has also spoken in favour of reform - Marilyn Stowe blog 24th April 2018.
In the Court of Appeal, Sir James Munby said (para 95) - "The hypocrisy and lack of intellectual honesty which is so characteristic a feature of the current law and procedure differs only in magnitude from the hypocrisy and lack of intellectual honesty which characterised the 'hotel divorce' under the old law, so mercilessly satirised in 1934 first by Evelyn Waugh in A Handful of Dust and then by A P Herbert in Holy Deadlock and, in the post-war world, more soberly described by Sir Robin Dunn in Sword and Wig, Memoirs of a Lord Justice, 1993, pp 139-140. Too often the modern 'behaviour' petition is little more than a charade. The 'hotel divorce' centred on a charade played out in front of the chambermaid or private inquiry agent who then gave evidence of events which would enable a judge, who either was or affected to be credulous, to find that adultery had been committed even though the services provided by the unnamed woman found in the respondent's bed when breakfast was taken in usually did not include the sexual intercourse which was, as it remains, essential to the act of adultery. That particular charade 'worked' because of the legal principle that adultery could be inferred if there was inclination and opportunity; the modern charade 'works' because of the operation of the rule of pleading ....., that if a claim is conceded it goes through in effect by default.
Hypocritical or not, reform seems likely be some time in coming if only because of the demands of Brexit on Parliament.
In 2016 there were 106,959 divorces of same sex couples - see HERE.
Same sex marriage and civil partnership:
The Marriage (Same Sex Couples) Act 2013 states that in England and Wales legislation a reference to marriage is to be read as including a reference to marriage of a same sex couple.
The Civil Partnership Act 2004 created civil partnerships for same sex couples and provides that such a partnership ends only on death, dissolution or annulment. Irretrievable breakdown is the basis for dissolution - see section 1(3) and also section 44.
Opposite sex couples and civil partnership:
Rebecca Steinfeld, 36, and Charles Keidan, 40, from west London, wish to have a civil partnership rather than a marriage and they argue that the government's position is "incompatible with equality law." Their case in the Court of Appeal is at  EWCA Civ 81. Their appeal to the Supreme Court was heard on 14th May 2018 - for further details see HERE.
History of Divorce - English legal history blog
Is there any point in defending a divorce - John Bolch on the Marilyn Stowe blog.