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Researched quite a lot of my family tree and only came across one case where the double barrelled name lasted more than one generation. I think the woman was from a relatively wealthy family so presume the name was important to her. After a couple of generations it appears to have been dropped and people just had the single surname. Other times, it was just that the woman kept her maiden name and double-barreled it with her husband's but didn't give it to the children. So I don't think it's a common practice historically in the UK.
What seems to be very popular with the Scots was giving the mother's maiden name as a middle name to the first daughter born.
My DH and I both double-barrelled when we married - Hyphens aren't particularly a new invention (e.g. http://en.wikipedia.org/wiki/Gough-Calthorpe_family ) - but historically they were mainly used in upper-class families where significant property was to be inherited through a female line and the woman's husband was required to take her name if he wanted the money. They have enjoyed a resurgence lately as more people object to following patriarchal traditions.
Personally, while I feel the symbolism of having a shared surname with DH is very important to me, and it was good that we both changed rather than just one of us, living with a double-barrelled surname is inconvenient and combersome. People tend to assume that I'm posher than I really am, which I find embarrassing, and it takes forever to spell my name.
If I was making the choice again, I would have pushed harder to get him to agree to the other option we considered, which was to create a new, normal-length surname using some of the letters of each of our previous surnames. This would have the advantage that it can be repeated each generation - whereas double-barrelling is clearly unsustainable in the long-term.