Apologies I mustn't have made myself clear, what I was actually asking was what you get from being married that wasn't already there between you and your partner as a couple, i.e. what was the motivation to get married with marriage if you already presumably had a great relationship.
This thread cropped up in another forum I belong to. This is what I said there:
From a purely pragmatic perspective, a marriage simplifies an enormous amount of legal issues. Were a couple to go through the steps of obtaining the legal documents that give them each the same benefits/protections that a marriage certificate does it would be a big hassel and cost quite a bit and might still not be "bulletproof" (I've heard of some very sad stories about gay couples who had all the documents and things still went terribly wrong).
When a couple that has been living together breaks up, even assuming no real estate or children are involved, there's the whole "sorting out the pots and pans" as I've heard television court judges call it. If you live together long enough, sooner or later your stuff/money starts getting mixed together. And if it's a bitter breakup, you can end up with people arguing, in court, over very, very stupid things.
And then there's the unpleasant but very real side of things. If you're married, and your spouse dies, even if they die without a will, where their "stuff" goes isn't in question. Your spouse's stuff is yours and NOBODY can legally take it from you (well, other than creditors and the tax collectors). However, if you have been living together, particularly if it's been for only a year or two (so there is no potential of claiming common-law marriage) and someone dies without leaving a will, things have the potential to get very, very ugly very, very fast. It's bad enough losing someone you love unexpectedly. Imagine having no say in where they get buried, how they are memorialized, and then having their family go through your home, take your beloved's stuff. Yes, it's the worst case scenario but it's happened plenty of times to many people.
Marriage certificates help smooth painful life transitions, you get a tax break and it used to be that there was no provision for "domestic partner" in most health insurance policy (that's started changing recently in the U.S.)
Oh, yeah, and if you or your s/o are of a nefarious bend, spouses cannot be legally compelled to testify against each other, at least so far as marital communications are concerned (IOW, if you tell your wife you killed someone, she cannot be made to testify in a court of law that you said that to her ... now if you kill the person in front of her, different story).
As to my case, I married my husband because at the time his finances were a mess and I needed health insurance. The marriage streamlined the handling of those things, in addition to some other stuff.
And there are plenty of men who want the security and "contract" of a marriage, too.